diff --git a/l10n_es_aeat_mod303_special_prorate_regularization/pyproject.toml b/l10n_es_aeat_mod303_special_prorate_regularization/pyproject.toml
new file mode 100644
index 000000000..4231d0ccc
--- /dev/null
+++ b/l10n_es_aeat_mod303_special_prorate_regularization/pyproject.toml
@@ -0,0 +1,3 @@
+[build-system]
+requires = ["whool"]
+build-backend = "whool.buildapi"
diff --git a/l10n_es_aeat_vat_special_prorrate/README.rst b/l10n_es_aeat_vat_special_prorrate/README.rst
new file mode 100644
index 000000000..f86f3448f
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/README.rst
@@ -0,0 +1,64 @@
+===============================
+AEAT - Prorrata especial de IVA
+===============================
+
+.. 
+   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+   !! This file is generated by oca-gen-addon-readme !!
+   !! changes will be overwritten.                   !!
+   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+   !! source digest: sha256:ca80aae12d33d2f1db6d6660cfa349770386cbcf591c27f04c6610f447414223
+   !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+.. |badge1| image:: https://img.shields.io/badge/maturity-Beta-yellow.png
+    :target: https://odoo-community.org/page/development-status
+    :alt: Beta
+.. |badge2| image:: https://img.shields.io/badge/licence-AGPL--3-blue.png
+    :target: http://www.gnu.org/licenses/agpl-3.0-standalone.html
+    :alt: License: AGPL-3
+.. |badge3| image:: https://img.shields.io/badge/github-NuoBiT%2Fodoo--addons-lightgray.png?logo=github
+    :target: https://github.com/NuoBiT/odoo-addons/tree/18.0/l10n_es_aeat_vat_special_prorrate
+    :alt: NuoBiT/odoo-addons
+
+|badge1| |badge2| |badge3|
+
+   Módulo para gestionar la prorrata especial del IVA en las facturas de
+   la AEAT
+
+**Table of contents**
+
+.. contents::
+   :local:
+
+Bug Tracker
+===========
+
+Bugs are tracked on `GitHub Issues <https://github.com/NuoBiT/odoo-addons/issues>`_.
+In case of trouble, please check there if your issue has already been reported.
+If you spotted it first, help us to smash it by providing a detailed and welcomed
+`feedback <https://github.com/NuoBiT/odoo-addons/issues/new?body=module:%20l10n_es_aeat_vat_special_prorrate%0Aversion:%2018.0%0A%0A**Steps%20to%20reproduce**%0A-%20...%0A%0A**Current%20behavior**%0A%0A**Expected%20behavior**>`_.
+
+Do not contact contributors directly about support or help with technical issues.
+
+Credits
+=======
+
+Authors
+-------
+
+* NuoBiT Solutions SL
+
+Contributors
+------------
+
+- `NuoBiT <https://www.nuobit.com>`__:
+
+  - Eric Antones eantones@nuobit.com
+  - Deniz Gallo dgallo@nuobit.com
+
+Maintainers
+-----------
+
+This module is part of the `NuoBiT/odoo-addons <https://github.com/NuoBiT/odoo-addons/tree/18.0/l10n_es_aeat_vat_special_prorrate>`_ project on GitHub.
+
+You are welcome to contribute.
diff --git a/l10n_es_aeat_vat_special_prorrate/__init__.py b/l10n_es_aeat_vat_special_prorrate/__init__.py
new file mode 100644
index 000000000..0650744f6
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/__init__.py
@@ -0,0 +1 @@
+from . import models
diff --git a/l10n_es_aeat_vat_special_prorrate/__manifest__.py b/l10n_es_aeat_vat_special_prorrate/__manifest__.py
new file mode 100644
index 000000000..1ca37460a
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/__manifest__.py
@@ -0,0 +1,24 @@
+# Copyright NuoBiT Solutions SL - Eric Antones <eantones@nuobit.com>
+# Copyright 2026 NuoBiT Solutions SL - Deniz Gallo <dgallo@nuobit.com>
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
+
+{
+    "name": "AEAT - Prorrata especial de IVA",
+    "summary": "Módulo para gestionar la prorrata especial del IVA "
+    "en las facturas de la AEAT",
+    "version": "18.0.1.0.0",
+    "category": "Accounting",
+    "author": "NuoBiT Solutions SL",
+    "website": "https://github.com/NuoBiT/odoo-addons",
+    "license": "AGPL-3",
+    "depends": [
+        "l10n_es_aeat_mod303",
+        "l10n_es_special_prorate",
+    ],
+    "data": [
+        "security/ir.model.access.csv",
+        "security/aeat_map_special_prorrate_year.xml",
+        "views/aeat_map_special_prorrate_year_views.xml",
+        "views/res_company_view.xml",
+    ],
+}
diff --git a/l10n_es_aeat_vat_special_prorrate/i18n/es.po b/l10n_es_aeat_vat_special_prorrate/i18n/es.po
new file mode 100644
index 000000000..693ed3261
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/i18n/es.po
@@ -0,0 +1,265 @@
+# This file contains the translation of the following modules:
+#	* l10n_es_aeat_vat_special_prorrate
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: Odoo Server 14.0\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2022-02-04 09:38+0000\n"
+"PO-Revision-Date: 2022-02-04 09:38+0000\n"
+"Last-Translator: \n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: \n"
+"Plural-Forms: \n"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: sql_constraint:aeat.map.special.prorrate.year:0
+msgid "AEAT year must be unique"
+msgstr "AEAT year must be unique"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.actions.act_window,name:l10n_es_aeat_vat_special_prorrate.action_aeat_map_special_prorrate_year
+#: model:ir.ui.menu,name:l10n_es_aeat_vat_special_prorrate.menu_aeat_map_special_prorrate_year
+#: model_terms:ir.ui.view,arch_db:l10n_es_aeat_vat_special_prorrate.aeat_map_special_prorrate_year_view_form
+#: model_terms:ir.ui.view,arch_db:l10n_es_aeat_vat_special_prorrate.aeat_map_special_prorrate_year_view_tree
+msgid "Aeat VAT special prorate map"
+msgstr "AEAT prorrata especial IVA - Mapeo anual"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model_terms:ir.ui.view,arch_db:l10n_es_aeat_vat_special_prorrate.aeat_map_special_prorrate_year_view_form
+msgid "Close"
+msgstr "Cerrar"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:35
+#: selection:aeat.map.special.prorrate.year,state:0
+#, python-format
+msgid "Closed"
+msgstr "Cerrado"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__company_id
+msgid "Company"
+msgstr "Compañía"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model_terms:ir.ui.view,arch_db:l10n_es_aeat_vat_special_prorrate.aeat_map_special_prorrate_year_view_form
+msgid "Compute"
+msgstr "Calcular"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__create_uid
+msgid "Created by"
+msgstr "Creado por"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__create_date
+msgid "Created on"
+msgstr "Creado el"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: selection:account.tax,prorrate_type:0
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/account_tax.py:14
+#, python-format
+msgid "Deductible"
+msgstr "Deducible"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__display_name
+msgid "Display Name"
+msgstr "Nombre mostrado"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__tax_final_percentage
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__tax_final_percentage_aux
+msgid "Final tax %"
+msgstr "Impuesto definitivo %"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:34
+#: selection:aeat.map.special.prorrate.year,state:0
+#, python-format
+msgid "Finale"
+msgstr "Final"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__id
+msgid "ID"
+msgstr "ID"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/account_tax.py:26
+#, python-format
+msgid "If a tax has prorate the year should exist on vat mapping"
+msgstr "If a tax has prorate the year should exist on vat mapping"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/account_tax.py:59
+#, python-format
+msgid "If a tax has prorate, it's only suported 'percent' type with price not included"
+msgstr "If a tax has prorate, it's only suported 'percent' type with price not included"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model,name:l10n_es_aeat_vat_special_prorrate.model_account_invoice
+msgid "Invoice"
+msgstr "Factura"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:85
+#, python-format
+msgid "It's not possible to delete a closed prorate map"
+msgstr "It's not possible to delete a closed prorate map"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:196
+#, python-format
+msgid "It's not possible to recompute a closed prorate"
+msgstr "It's not possible to recompute a closed prorate"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_res_company__l10n_es_prorate_enabled
+msgid "L10n ES Prorate Enabled"
+msgstr "L10n ES prorrata activada"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model_terms:ir.ui.view,arch_db:l10n_es_aeat_vat_special_prorrate.view_company_aeat_form
+msgid "Prorate"
+msgstr "Prorrata"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year____last_update
+msgid "Last Modified on"
+msgstr "Última modificación en"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__write_uid
+msgid "Last Updated by"
+msgstr "Última actualización por"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__write_date
+msgid "Last Updated on"
+msgstr "Última actualización el"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__map_prorrate_next_year_id
+msgid "Map Prorate Next Year"
+msgstr "Map Prorate Next Year"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/account_tax.py:68
+#, python-format
+msgid "Multiple taxes with the same prorate type under same parent is not suported"
+msgstr "Multiple taxes with the same prorate type under same parent is not suported"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: selection:account.tax,prorrate_type:0
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/account_tax.py:14
+#, python-format
+msgid "Non-deductible"
+msgstr "No deducible"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/account_invoice.py:33
+#, python-format
+msgid "Only suported 'percent' type with price not included"
+msgstr "Only suported 'percent' type with price not included"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_account_tax__prorrate_type
+msgid "Prorate type"
+msgstr "Tipo de prorrata"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model_terms:ir.ui.view,arch_db:l10n_es_aeat_vat_special_prorrate.aeat_map_special_prorrate_year_view_form
+msgid "Recompute"
+msgstr "Recalcular"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/account_tax.py:0
+#, python-format
+msgid ""
+"Runtime error: Prorate tax '%s' has %i %s repartition lines instead of "
+"expected 2. This may indicate data corruption or constraint bypass."
+msgstr "Error de ejecución: El impuesto de prorrata '%s' tiene %i líneas de reparto de %s en "
+"lugar de las 2 esperadas. Esto puede indicar corrupción de datos o elusión de "
+"restricciones."
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model_terms:ir.ui.view,arch_db:l10n_es_aeat_vat_special_prorrate.aeat_map_special_prorrate_year_view_form
+msgid "Set to Temporary"
+msgstr "Establecer a provisional"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__state
+msgid "State"
+msgstr "Estado"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model,name:l10n_es_aeat_vat_special_prorrate.model_account_tax
+msgid "Tax"
+msgstr "Impuesto"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__tax_percentage
+msgid "Tax %"
+msgstr "Impuesto %"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:33
+#: selection:aeat.map.special.prorrate.year,state:0
+#, python-format
+msgid "Temporary"
+msgstr "Provisional"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:223
+#, python-format
+msgid "The final prorrate computed should be greater than zero"
+msgstr "The final prorrate computed should be greater than zero"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: sql_constraint:aeat.map.special.prorrate.year:0
+msgid "The map prorrate must have one next prorrate only"
+msgstr "The map prorrate must have one next prorrate only"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:209
+#, python-format
+msgid "The previous state to be able to close a prorrate should be 'Finale', not '%s'"
+msgstr "The previous state to be able to close a prorrate should be 'Finale', not '%s'"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:200
+#, python-format
+msgid "The prorrate of previous year must be closed before compute the new one"
+msgstr "The prorrate of previous year must be closed before compute the new one"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:73
+#, python-format
+msgid "The year of the next linked map prorrata must be the next chronological year"
+msgstr "The year of the next linked map prorrata must be the next chronological year"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: code:addons/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py:79
+#, python-format
+msgid "The year of the previous linked map prorrata must be the previous chronological year"
+msgstr "The year of the previous linked map prorrata must be the previous chronological year"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model.fields,field_description:l10n_es_aeat_vat_special_prorrate.field_aeat_map_special_prorrate_year__year
+msgid "Year"
+msgstr "Año"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model,name:l10n_es_aeat_vat_special_prorrate.model_aeat_map_special_prorrate_year
+msgid "aeat.map.special.prorrate.year"
+msgstr "aeat.map.special.prorrate.year"
+
+#. module: l10n_es_aeat_vat_special_prorrate
+#: model:ir.model,name:l10n_es_aeat_vat_special_prorrate.model_l10n_es_aeat_report_tax_mapping_transient
+msgid "l10n.es.aeat.report.tax.mapping.transient"
+msgstr "l10n.es.aeat.report.tax.mapping.transient"
diff --git a/l10n_es_aeat_vat_special_prorrate/models/__init__.py b/l10n_es_aeat_vat_special_prorrate/models/__init__.py
new file mode 100644
index 000000000..bd68f440a
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/models/__init__.py
@@ -0,0 +1,5 @@
+from . import aeat_map_special_prorrate_year
+from . import account_tax
+from . import account_tax_repartition_line
+from . import account_move
+from . import res_company
diff --git a/l10n_es_aeat_vat_special_prorrate/models/account_move.py b/l10n_es_aeat_vat_special_prorrate/models/account_move.py
new file mode 100644
index 000000000..7cfa036de
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/models/account_move.py
@@ -0,0 +1,27 @@
+# Copyright NuoBiT Solutions SL - Eric Antones <eantones@nuobit.com>
+# Copyright 2026 NuoBiT Solutions SL - Deniz Gallo <dgallo@nuobit.com>
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
+
+from odoo import models
+
+
+class AccountMove(models.Model):
+    _inherit = "account.move"
+
+    def _get_rounded_base_and_tax_lines(self, round_from_tax_lines=True):
+        if self.company_id.l10n_es_prorate_enabled and not self.env.context.get(
+            "prorate"
+        ):
+            prorate_ctx = self.env["account.tax"].prorate_context(
+                self,
+                self.date,
+                self.company_id,
+            )
+            return super(
+                AccountMove, self.with_context(**prorate_ctx)
+            )._get_rounded_base_and_tax_lines(
+                round_from_tax_lines=round_from_tax_lines,
+            )
+        return super()._get_rounded_base_and_tax_lines(
+            round_from_tax_lines=round_from_tax_lines,
+        )
diff --git a/l10n_es_aeat_vat_special_prorrate/models/account_tax.py b/l10n_es_aeat_vat_special_prorrate/models/account_tax.py
new file mode 100644
index 000000000..2a0e4d3a7
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/models/account_tax.py
@@ -0,0 +1,69 @@
+# Copyright NuoBiT Solutions SL - Eric Antones <eantones@nuobit.com>
+# Copyright 2026 NuoBiT Solutions SL - Deniz Gallo <dgallo@nuobit.com>
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
+
+from odoo import models
+from odoo.exceptions import ValidationError
+from odoo.tools.translate import _
+
+
+class AccountTax(models.Model):
+    _inherit = "account.tax"
+
+    def compute_all(
+        self,
+        price_unit,
+        currency=None,
+        quantity=1.0,
+        product=None,
+        partner=None,
+        is_refund=False,
+        handle_price_include=True,
+    ):
+        res = super().compute_all(
+            price_unit,
+            currency=currency,
+            quantity=quantity,
+            product=product,
+            partner=partner,
+            is_refund=is_refund,
+            handle_price_include=handle_price_include,
+        )
+        # group repartition lines by tax
+        # Sort the taxes so that those without account_id come last. This is
+        # to have an Odoo like behavior when no rounding errors occur.
+        sorted_taxes = sorted(
+            res["taxes"], key=lambda x: x["account_id"] in (None, False)
+        )
+        rlines_by_tax = {}
+        for tax in sorted_taxes:
+            rline = self.env["account.tax.repartition.line"].browse(
+                tax["tax_repartition_line_id"]
+            )
+            if rline and rline.tax_id.prorate:
+                rline_type = "invoice" if rline.invoice_tax_id else "refund"
+                if rline.repartition_type == "tax" and rline.factor_percent == 100.0:
+                    rlines_by_tax.setdefault((rline_type, rline.tax_id), []).append(tax)
+        # round the prorate pairs for each tax
+        for (rltype, tax), prorate_taxes in rlines_by_tax.items():
+            # Defensive check: constraint on account.tax should guarantee exactly
+            # 2 with 100% but protect against data corruption since we're gonna
+            # index this list.
+            if len(prorate_taxes) != 2:
+                raise ValidationError(
+                    _(
+                        "Runtime error: Prorate tax '%(tax_name)s' "
+                        "has %(lines_count)i %(rltype)s repartition "
+                        "lines instead of expected 2. This may indicate "
+                        "data corruption or constraint bypass."
+                    )
+                    % {
+                        "tax_name": tax.name,
+                        "lines_count": len(prorate_taxes),
+                        "rltype": rltype,
+                    }
+                )
+            base_tax_amount = sum(x["amount"] for x in prorate_taxes)
+            prorate_taxes[0]["amount"] = currency.round(prorate_taxes[0]["amount"])
+            prorate_taxes[1]["amount"] = base_tax_amount - prorate_taxes[0]["amount"]
+        return res
diff --git a/l10n_es_aeat_vat_special_prorrate/models/account_tax_repartition_line.py b/l10n_es_aeat_vat_special_prorrate/models/account_tax_repartition_line.py
new file mode 100644
index 000000000..b0ce781c9
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/models/account_tax_repartition_line.py
@@ -0,0 +1,57 @@
+# Copyright NuoBiT Solutions SL - Eric Antones <eantones@nuobit.com>
+# Copyright 2026 NuoBiT Solutions SL - Deniz Gallo <dgallo@nuobit.com>
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
+
+from odoo import api, fields, models
+from odoo.exceptions import ValidationError
+from odoo.tools.translate import _
+
+
+class AccountTaxRepartitionLine(models.Model):
+    _inherit = "account.tax.repartition.line"
+
+    def get_prorrate_ratio(self, date, company_id):
+        if self.repartition_type != "tax":
+            return 1
+        prorrate_map = self.env["aeat.map.special.prorrate.year"].search(
+            [
+                (
+                    "company_id",
+                    "=",
+                    company_id or self.tax_id.company_id.id or self.env.company.id,
+                ),
+                ("year", "=", date.year),
+            ]
+        )
+        if not prorrate_map:
+            raise ValidationError(
+                _("If a tax has prorate the year should exist on vat mapping")
+            )
+
+        prorate_ratio = prorrate_map.tax_percentage / 100
+        if not self.account_id:
+            prorate_ratio = 1 - prorate_ratio
+
+        return prorate_ratio
+
+    @api.depends_context("prorate")
+    def _compute_factor(self):
+        prorate = self.env.context.get("prorate")
+        if prorate:
+            date_str, company_id = prorate
+            prorate = (
+                fields.Date.to_date(date_str),
+                company_id,
+            )
+        for record in self.filtered(
+            lambda x: x.tax_id.prorate and prorate and x.factor_percent == 100.0
+        ):
+            record.factor = record.get_prorrate_ratio(*prorate)
+        return super(
+            AccountTaxRepartitionLine,
+            self.filtered(
+                lambda x: not x.tax_id.prorate
+                or not prorate
+                or x.factor_percent != 100.0
+            ),
+        )._compute_factor()
diff --git a/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py b/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py
new file mode 100644
index 000000000..b3e4f842e
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/models/aeat_map_special_prorrate_year.py
@@ -0,0 +1,241 @@
+# Copyright NuoBiT Solutions SL - Eric Antones <eantones@nuobit.com>
+# Copyright 2026 NuoBiT Solutions SL - Deniz Gallo <dgallo@nuobit.com>
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
+import math
+
+from odoo import api, fields, models
+from odoo.exceptions import UserError, ValidationError
+from odoo.tools.translate import _
+
+
+class MapSpecialProrateYear(models.Model):
+    _name = "aeat.map.special.prorrate.year"
+    _description = "Aeat VAT special prorate map"
+
+    company_id = fields.Many2one(
+        comodel_name="res.company",
+        string="Company",
+        required=True,
+        readonly=True,
+        default=lambda self: self.env.company,
+    )
+
+    def _default_year(self):
+        last = self.search(
+            [("company_id", "=", self.env.company.id)],
+            order="company_id,year desc",
+            limit=1,
+        )
+        return last and last.year + 1 or fields.Date.context_today(self).year
+
+    year = fields.Integer(default=_default_year, required=True)
+    tax_percentage = fields.Float(string="Temporary %", required=True)
+
+    map_prorrate_next_year_id = fields.Many2one(
+        comodel_name="aeat.map.special.prorrate.year",
+        ondelete="restrict",
+        required=False,
+        readonly=True,
+        store=True,
+    )
+
+    tax_final_percentage = fields.Float(
+        string="Final tax %",
+        readonly=True,
+        related="map_prorrate_next_year_id.tax_percentage",
+    )
+
+    tax_final_percentage_aux = fields.Float(string="Final tax % (aux)", readonly=True)
+
+    state = fields.Selection(
+        selection=[
+            ("temporary", "Temporary"),
+            ("finale", "Finale"),
+            ("closed", "Closed"),
+        ],
+        readonly=True,
+        default="temporary",
+        required=True,
+    )
+
+    _sql_constraints = [
+        ("unique_year", "unique(year, company_id)", "AEAT year must be unique"),
+        (
+            "unique_next",
+            "unique(map_prorrate_next_year_id)",
+            "The map prorate must have only one next year prorate",
+        ),
+    ]
+
+    @api.model
+    def get_by_ukey(self, company_id, year):
+        return self.search(
+            [
+                ("company_id", "=", company_id),
+                ("year", "=", year),
+            ]
+        )
+
+    def get_previous(self):
+        return self.search(
+            [
+                ("map_prorrate_next_year_id", "=", self.id),
+            ]
+        )
+
+    @api.depends("year", "tax_percentage", "tax_final_percentage")
+    def _compute_display_name(self):
+        for rec in self:
+            percents = [rec.tax_percentage]
+            if rec.tax_final_percentage:
+                percents.append(rec.tax_final_percentage)
+            name_l = [f"{round(x, 2):g}" for x in percents]
+            rec.display_name = "%i: %s" % (rec.year, " -> ".join(name_l))
+
+    @api.constrains("map_prorrate_next_year_id", "year")
+    def _check_map_prorate_next_year(self):
+        for rec in self:
+            if (
+                rec.map_prorrate_next_year_id
+                and rec.map_prorrate_next_year_id.year != rec.year + 1
+            ):
+                raise ValidationError(
+                    _(
+                        "The year of the next linked map prorrata must be "
+                        "the next chronological year"
+                    )
+                )
+
+            map_prorate_previous_year_id = rec.get_previous()
+            if (
+                map_prorate_previous_year_id
+                and map_prorate_previous_year_id.year != rec.year - 1
+            ):
+                raise ValidationError(
+                    _(
+                        "The year of the previous linked map prorrata must be "
+                        "the previous chronological year"
+                    )
+                )
+
+    def unlink(self):
+        for rec in self:
+            if rec.state == "closed":
+                raise ValidationError(
+                    _("It's not possible to delete a closed prorate map")
+                )
+            map_prorate_previous_year_id = rec.get_previous()
+            if map_prorate_previous_year_id.state == "temporary":
+                map_prorate_previous_year_id.map_prorrate_next_year_id = False
+            return super(MapSpecialProrateYear, rec).unlink()
+
+    def _compute_prorate_percent(self):
+        self.ensure_one()
+        date_from = f"{self.year}-01-01"
+        date_to = f"{self.year}-12-31"
+
+        mod303 = self.env["l10n.es.aeat.mod303.report"].new(
+            {"company_id": self.company_id.id}
+        )
+
+        MapLine = self.env["l10n.es.aeat.map.tax.line"]
+        MapLineTax = self.env["l10n.es.aeat.map.tax.line.tax"]
+
+        def _get_tax_xmlid_ids(xmlid_names):
+            return MapLineTax.search([("name", "in", xmlid_names)])
+
+        taxed_names = [
+            "account_tax_template_s_iva4b",
+            "account_tax_template_s_iva4s",
+            "account_tax_template_s_iva10b",
+            "account_tax_template_s_iva10s",
+            "account_tax_template_s_iva21b",
+            "account_tax_template_s_iva21s",
+            "account_tax_template_s_iva21isp",
+        ]
+        mapline_vals = {
+            "move_type": "all",
+            "field_type": "base",
+            "sum_type": "both",
+            "exigible_type": "yes",
+            "tax_xmlid_ids": _get_tax_xmlid_ids(taxed_names),
+        }
+        map_line = MapLine.new(mapline_vals)
+        move_lines = mod303._get_tax_lines(date_from, date_to, map_line)
+        taxed = -sum(move_lines.mapped("balance"))
+
+        # Get base amount of exempt operations
+        exempt_names = [
+            "account_tax_template_s_iva0",
+            "account_tax_template_s_iva0_ns",
+        ]
+        mapline_vals["tax_xmlid_ids"] = _get_tax_xmlid_ids(exempt_names)
+        map_line = MapLine.new(mapline_vals)
+        move_lines = mod303._get_tax_lines(date_from, date_to, map_line)
+        exempt = -sum(move_lines.mapped("balance"))
+
+        if not taxed and not exempt:
+            raise UserError(_("No taxable or exempt operations found"))
+        # Compute prorate percentage performing ceiling operation
+        return math.ceil(taxed / (taxed + exempt) * 100)
+
+    def compute_prorate(self):
+        self.ensure_one()
+
+        if self.state == "close":
+            raise ValidationError(
+                _("It's not possible to recompute a closed prorate") % self.state
+            )
+
+        prorate_map_previous_year = self.get_by_ukey(self.company_id.id, self.year - 1)
+        if prorate_map_previous_year and prorate_map_previous_year.state != "closed":
+            raise ValidationError(
+                _(
+                    "The prorate of previous year must be "
+                    "closed before compute the new one"
+                )
+            )
+
+        self.tax_final_percentage_aux = self._compute_prorate_percent()
+        self.state = "finale"
+
+    def close_prorate(self):
+        self.ensure_one()
+        if self.state not in ("finale",):
+            raise ValidationError(
+                _(
+                    "The previous state to be able to close a prorate "
+                    "should be 'Finale', not '%s'"
+                )
+                % self.state
+            )
+
+        if self.map_prorrate_next_year_id:
+            if (
+                self.map_prorrate_next_year_id.tax_percentage
+                != self.tax_final_percentage_aux
+            ):
+                self.map_prorrate_next_year_id.write(
+                    {
+                        "tax_percentage": self.tax_final_percentage_aux,
+                    }
+                )
+        else:
+            self.map_prorrate_next_year_id = self.create(
+                [
+                    {
+                        "year": self.year + 1,
+                        "tax_percentage": self.tax_final_percentage_aux,
+                    }
+                ]
+            )
+        self.state = "closed"
+
+        if self.tax_final_percentage <= 0:
+            raise ValidationError(
+                _("The final prorate computed should be greater than zero")
+            )
+
+    def set_temporary(self):
+        self.tax_final_percentage_aux = False
+        self.state = "temporary"
diff --git a/l10n_es_aeat_vat_special_prorrate/models/res_company.py b/l10n_es_aeat_vat_special_prorrate/models/res_company.py
new file mode 100644
index 000000000..54449d9a7
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/models/res_company.py
@@ -0,0 +1,10 @@
+# Copyright NuoBiT Solutions SL - Kilian Niubo <kniubo@nuobit.com>
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
+
+from odoo import fields, models
+
+
+class ResCompany(models.Model):
+    _inherit = "res.company"
+
+    l10n_es_prorate_enabled = fields.Boolean(string="L10n ES Prorate Enabled")
diff --git a/l10n_es_aeat_vat_special_prorrate/pyproject.toml b/l10n_es_aeat_vat_special_prorrate/pyproject.toml
new file mode 100644
index 000000000..4231d0ccc
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/pyproject.toml
@@ -0,0 +1,3 @@
+[build-system]
+requires = ["whool"]
+build-backend = "whool.buildapi"
diff --git a/l10n_es_aeat_vat_special_prorrate/readme/CONTRIBUTORS.md b/l10n_es_aeat_vat_special_prorrate/readme/CONTRIBUTORS.md
new file mode 100644
index 000000000..909507cba
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/readme/CONTRIBUTORS.md
@@ -0,0 +1,3 @@
+- [NuoBiT](https://www.nuobit.com):
+  - Eric Antones <eantones@nuobit.com>
+  - Deniz Gallo <dgallo@nuobit.com>
diff --git a/l10n_es_aeat_vat_special_prorrate/readme/DESCRIPTION.md b/l10n_es_aeat_vat_special_prorrate/readme/DESCRIPTION.md
new file mode 100644
index 000000000..9895c15bd
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/readme/DESCRIPTION.md
@@ -0,0 +1,2 @@
+> Módulo para gestionar la prorrata especial del IVA en las facturas de
+> la AEAT
diff --git a/l10n_es_aeat_vat_special_prorrate/security/aeat_map_special_prorrate_year.xml b/l10n_es_aeat_vat_special_prorrate/security/aeat_map_special_prorrate_year.xml
new file mode 100644
index 000000000..d148b37dd
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/security/aeat_map_special_prorrate_year.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!-- Copyright NuoBiT - Eric Antones <eantones@nuobit.com>
+     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl) -->
+<odoo noupdate="1">
+    <record id="aeat_map_special_prorrate_year_company_rule" model="ir.rule">
+        <field name="name">Aeat VAT special prorate map multi-company rule</field>
+        <field name="model_id" ref="model_aeat_map_special_prorrate_year" />
+        <field
+            name="domain_force"
+        >['|', ('company_id', '=', False), ('company_id', 'in', company_ids)]</field>
+    </record>
+</odoo>
diff --git a/l10n_es_aeat_vat_special_prorrate/security/ir.model.access.csv b/l10n_es_aeat_vat_special_prorrate/security/ir.model.access.csv
new file mode 100644
index 000000000..f79a0df0c
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/security/ir.model.access.csv
@@ -0,0 +1,3 @@
+"id","name","model_id:id","group_id:id","perm_read","perm_write","perm_create","perm_unlink"
+"access_aeat_map_special_prorrate_year_user","Aeat VAT special prorrate map - Account User","model_aeat_map_special_prorrate_year","account.group_account_invoice",1,0,0,0
+"access_aeat_map_special_prorrate_year_manager","Aeat VAT special prorrate map - Account Manager","model_aeat_map_special_prorrate_year","account.group_account_manager",1,1,1,1
diff --git a/l10n_es_aeat_vat_special_prorrate/static/description/icon.png b/l10n_es_aeat_vat_special_prorrate/static/description/icon.png
new file mode 100644
index 000000000..1cd641e79
Binary files /dev/null and b/l10n_es_aeat_vat_special_prorrate/static/description/icon.png differ
diff --git a/l10n_es_aeat_vat_special_prorrate/static/description/index.html b/l10n_es_aeat_vat_special_prorrate/static/description/index.html
new file mode 100644
index 000000000..2f10af06d
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/static/description/index.html
@@ -0,0 +1,422 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+<meta name="generator" content="Docutils: https://docutils.sourceforge.io/" />
+<title>AEAT - Prorrata especial de IVA</title>
+<style type="text/css">
+
+/*
+:Author: David Goodger (goodger@python.org)
+:Id: $Id: html4css1.css 9511 2024-01-13 09:50:07Z milde $
+:Copyright: This stylesheet has been placed in the public domain.
+
+Default cascading style sheet for the HTML output of Docutils.
+Despite the name, some widely supported CSS2 features are used.
+
+See https://docutils.sourceforge.io/docs/howto/html-stylesheets.html for how to
+customize this style sheet.
+*/
+
+/* used to remove borders from tables and images */
+.borderless, table.borderless td, table.borderless th {
+  border: 0 }
+
+table.borderless td, table.borderless th {
+  /* Override padding for "table.docutils td" with "! important".
+     The right padding separates the table cells. */
+  padding: 0 0.5em 0 0 ! important }
+
+.first {
+  /* Override more specific margin styles with "! important". */
+  margin-top: 0 ! important }
+
+.last, .with-subtitle {
+  margin-bottom: 0 ! important }
+
+.hidden {
+  display: none }
+
+.subscript {
+  vertical-align: sub;
+  font-size: smaller }
+
+.superscript {
+  vertical-align: super;
+  font-size: smaller }
+
+a.toc-backref {
+  text-decoration: none ;
+  color: black }
+
+blockquote.epigraph {
+  margin: 2em 5em ; }
+
+dl.docutils dd {
+  margin-bottom: 0.5em }
+
+object[type="image/svg+xml"], object[type="application/x-shockwave-flash"] {
+  overflow: hidden;
+}
+
+/* Uncomment (and remove this text!) to get bold-faced definition list terms
+dl.docutils dt {
+  font-weight: bold }
+*/
+
+div.abstract {
+  margin: 2em 5em }
+
+div.abstract p.topic-title {
+  font-weight: bold ;
+  text-align: center }
+
+div.admonition, div.attention, div.caution, div.danger, div.error,
+div.hint, div.important, div.note, div.tip, div.warning {
+  margin: 2em ;
+  border: medium outset ;
+  padding: 1em }
+
+div.admonition p.admonition-title, div.hint p.admonition-title,
+div.important p.admonition-title, div.note p.admonition-title,
+div.tip p.admonition-title {
+  font-weight: bold ;
+  font-family: sans-serif }
+
+div.attention p.admonition-title, div.caution p.admonition-title,
+div.danger p.admonition-title, div.error p.admonition-title,
+div.warning p.admonition-title, .code .error {
+  color: red ;
+  font-weight: bold ;
+  font-family: sans-serif }
+
+/* Uncomment (and remove this text!) to get reduced vertical space in
+   compound paragraphs.
+div.compound .compound-first, div.compound .compound-middle {
+  margin-bottom: 0.5em }
+
+div.compound .compound-last, div.compound .compound-middle {
+  margin-top: 0.5em }
+*/
+
+div.dedication {
+  margin: 2em 5em ;
+  text-align: center ;
+  font-style: italic }
+
+div.dedication p.topic-title {
+  font-weight: bold ;
+  font-style: normal }
+
+div.figure {
+  margin-left: 2em ;
+  margin-right: 2em }
+
+div.footer, div.header {
+  clear: both;
+  font-size: smaller }
+
+div.line-block {
+  display: block ;
+  margin-top: 1em ;
+  margin-bottom: 1em }
+
+div.line-block div.line-block {
+  margin-top: 0 ;
+  margin-bottom: 0 ;
+  margin-left: 1.5em }
+
+div.sidebar {
+  margin: 0 0 0.5em 1em ;
+  border: medium outset ;
+  padding: 1em ;
+  background-color: #ffffee ;
+  width: 40% ;
+  float: right ;
+  clear: right }
+
+div.sidebar p.rubric {
+  font-family: sans-serif ;
+  font-size: medium }
+
+div.system-messages {
+  margin: 5em }
+
+div.system-messages h1 {
+  color: red }
+
+div.system-message {
+  border: medium outset ;
+  padding: 1em }
+
+div.system-message p.system-message-title {
+  color: red ;
+  font-weight: bold }
+
+div.topic {
+  margin: 2em }
+
+h1.section-subtitle, h2.section-subtitle, h3.section-subtitle,
+h4.section-subtitle, h5.section-subtitle, h6.section-subtitle {
+  margin-top: 0.4em }
+
+h1.title {
+  text-align: center }
+
+h2.subtitle {
+  text-align: center }
+
+hr.docutils {
+  width: 75% }
+
+img.align-left, .figure.align-left, object.align-left, table.align-left {
+  clear: left ;
+  float: left ;
+  margin-right: 1em }
+
+img.align-right, .figure.align-right, object.align-right, table.align-right {
+  clear: right ;
+  float: right ;
+  margin-left: 1em }
+
+img.align-center, .figure.align-center, object.align-center {
+  display: block;
+  margin-left: auto;
+  margin-right: auto;
+}
+
+table.align-center {
+  margin-left: auto;
+  margin-right: auto;
+}
+
+.align-left {
+  text-align: left }
+
+.align-center {
+  clear: both ;
+  text-align: center }
+
+.align-right {
+  text-align: right }
+
+/* reset inner alignment in figures */
+div.align-right {
+  text-align: inherit }
+
+/* div.align-center * { */
+/*   text-align: left } */
+
+.align-top    {
+  vertical-align: top }
+
+.align-middle {
+  vertical-align: middle }
+
+.align-bottom {
+  vertical-align: bottom }
+
+ol.simple, ul.simple {
+  margin-bottom: 1em }
+
+ol.arabic {
+  list-style: decimal }
+
+ol.loweralpha {
+  list-style: lower-alpha }
+
+ol.upperalpha {
+  list-style: upper-alpha }
+
+ol.lowerroman {
+  list-style: lower-roman }
+
+ol.upperroman {
+  list-style: upper-roman }
+
+p.attribution {
+  text-align: right ;
+  margin-left: 50% }
+
+p.caption {
+  font-style: italic }
+
+p.credits {
+  font-style: italic ;
+  font-size: smaller }
+
+p.label {
+  white-space: nowrap }
+
+p.rubric {
+  font-weight: bold ;
+  font-size: larger ;
+  color: maroon ;
+  text-align: center }
+
+p.sidebar-title {
+  font-family: sans-serif ;
+  font-weight: bold ;
+  font-size: larger }
+
+p.sidebar-subtitle {
+  font-family: sans-serif ;
+  font-weight: bold }
+
+p.topic-title {
+  font-weight: bold }
+
+pre.address {
+  margin-bottom: 0 ;
+  margin-top: 0 ;
+  font: inherit }
+
+pre.literal-block, pre.doctest-block, pre.math, pre.code {
+  margin-left: 2em ;
+  margin-right: 2em }
+
+pre.code .ln { color: gray; } /* line numbers */
+pre.code, code { background-color: #eeeeee }
+pre.code .comment, code .comment { color: #5C6576 }
+pre.code .keyword, code .keyword { color: #3B0D06; font-weight: bold }
+pre.code .literal.string, code .literal.string { color: #0C5404 }
+pre.code .name.builtin, code .name.builtin { color: #352B84 }
+pre.code .deleted, code .deleted { background-color: #DEB0A1}
+pre.code .inserted, code .inserted { background-color: #A3D289}
+
+span.classifier {
+  font-family: sans-serif ;
+  font-style: oblique }
+
+span.classifier-delimiter {
+  font-family: sans-serif ;
+  font-weight: bold }
+
+span.interpreted {
+  font-family: sans-serif }
+
+span.option {
+  white-space: nowrap }
+
+span.pre {
+  white-space: pre }
+
+span.problematic, pre.problematic {
+  color: red }
+
+span.section-subtitle {
+  /* font-size relative to parent (h1..h6 element) */
+  font-size: 80% }
+
+table.citation {
+  border-left: solid 1px gray;
+  margin-left: 1px }
+
+table.docinfo {
+  margin: 2em 4em }
+
+table.docutils {
+  margin-top: 0.5em ;
+  margin-bottom: 0.5em }
+
+table.footnote {
+  border-left: solid 1px black;
+  margin-left: 1px }
+
+table.docutils td, table.docutils th,
+table.docinfo td, table.docinfo th {
+  padding-left: 0.5em ;
+  padding-right: 0.5em ;
+  vertical-align: top }
+
+table.docutils th.field-name, table.docinfo th.docinfo-name {
+  font-weight: bold ;
+  text-align: left ;
+  white-space: nowrap ;
+  padding-left: 0 }
+
+/* "booktabs" style (no vertical lines) */
+table.docutils.booktabs {
+  border: 0px;
+  border-top: 2px solid;
+  border-bottom: 2px solid;
+  border-collapse: collapse;
+}
+table.docutils.booktabs * {
+  border: 0px;
+}
+table.docutils.booktabs th {
+  border-bottom: thin solid;
+  text-align: left;
+}
+
+h1 tt.docutils, h2 tt.docutils, h3 tt.docutils,
+h4 tt.docutils, h5 tt.docutils, h6 tt.docutils {
+  font-size: 100% }
+
+ul.auto-toc {
+  list-style-type: none }
+
+</style>
+</head>
+<body>
+<div class="document" id="aeat-prorrata-especial-de-iva">
+<h1 class="title">AEAT - Prorrata especial de IVA</h1>
+
+<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+!! This file is generated by oca-gen-addon-readme !!
+!! changes will be overwritten.                   !!
+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+!! source digest: sha256:ca80aae12d33d2f1db6d6660cfa349770386cbcf591c27f04c6610f447414223
+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->
+<p><a class="reference external image-reference" href="https://odoo-community.org/page/development-status"><img alt="Beta" src="https://img.shields.io/badge/maturity-Beta-yellow.png" /></a> <a class="reference external image-reference" href="http://www.gnu.org/licenses/agpl-3.0-standalone.html"><img alt="License: AGPL-3" src="https://img.shields.io/badge/licence-AGPL--3-blue.png" /></a> <a class="reference external image-reference" href="https://github.com/NuoBiT/odoo-addons/tree/18.0/l10n_es_aeat_vat_special_prorrate"><img alt="NuoBiT/odoo-addons" src="https://img.shields.io/badge/github-NuoBiT%2Fodoo--addons-lightgray.png?logo=github" /></a></p>
+<blockquote>
+Módulo para gestionar la prorrata especial del IVA en las facturas de
+la AEAT</blockquote>
+<p><strong>Table of contents</strong></p>
+<div class="contents local topic" id="contents">
+<ul class="simple">
+<li><a class="reference internal" href="#bug-tracker" id="toc-entry-1">Bug Tracker</a></li>
+<li><a class="reference internal" href="#credits" id="toc-entry-2">Credits</a><ul>
+<li><a class="reference internal" href="#authors" id="toc-entry-3">Authors</a></li>
+<li><a class="reference internal" href="#contributors" id="toc-entry-4">Contributors</a></li>
+<li><a class="reference internal" href="#maintainers" id="toc-entry-5">Maintainers</a></li>
+</ul>
+</li>
+</ul>
+</div>
+<div class="section" id="bug-tracker">
+<h1><a class="toc-backref" href="#toc-entry-1">Bug Tracker</a></h1>
+<p>Bugs are tracked on <a class="reference external" href="https://github.com/NuoBiT/odoo-addons/issues">GitHub Issues</a>.
+In case of trouble, please check there if your issue has already been reported.
+If you spotted it first, help us to smash it by providing a detailed and welcomed
+<a class="reference external" href="https://github.com/NuoBiT/odoo-addons/issues/new?body=module:%20l10n_es_aeat_vat_special_prorrate%0Aversion:%2018.0%0A%0A**Steps%20to%20reproduce**%0A-%20...%0A%0A**Current%20behavior**%0A%0A**Expected%20behavior**">feedback</a>.</p>
+<p>Do not contact contributors directly about support or help with technical issues.</p>
+</div>
+<div class="section" id="credits">
+<h1><a class="toc-backref" href="#toc-entry-2">Credits</a></h1>
+<div class="section" id="authors">
+<h2><a class="toc-backref" href="#toc-entry-3">Authors</a></h2>
+<ul class="simple">
+<li>NuoBiT Solutions SL</li>
+</ul>
+</div>
+<div class="section" id="contributors">
+<h2><a class="toc-backref" href="#toc-entry-4">Contributors</a></h2>
+<ul class="simple">
+<li><a class="reference external" href="https://www.nuobit.com">NuoBiT</a>:<ul>
+<li>Eric Antones <a class="reference external" href="mailto:eantones&#64;nuobit.com">eantones&#64;nuobit.com</a></li>
+<li>Deniz Gallo <a class="reference external" href="mailto:dgallo&#64;nuobit.com">dgallo&#64;nuobit.com</a></li>
+</ul>
+</li>
+</ul>
+</div>
+<div class="section" id="maintainers">
+<h2><a class="toc-backref" href="#toc-entry-5">Maintainers</a></h2>
+<p>This module is part of the <a class="reference external" href="https://github.com/NuoBiT/odoo-addons/tree/18.0/l10n_es_aeat_vat_special_prorrate">NuoBiT/odoo-addons</a> project on GitHub.</p>
+<p>You are welcome to contribute.</p>
+</div>
+</div>
+</div>
+</body>
+</html>
diff --git a/l10n_es_aeat_vat_special_prorrate/views/aeat_map_special_prorrate_year_views.xml b/l10n_es_aeat_vat_special_prorrate/views/aeat_map_special_prorrate_year_views.xml
new file mode 100644
index 000000000..62a8399e0
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/views/aeat_map_special_prorrate_year_views.xml
@@ -0,0 +1,89 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!-- Copyright NuoBiT Solutions SL - Eric Antones <eantones@nuobit.com>
+     Copyright 2026 NuoBiT Solutions SL - Deniz Gallo <dgallo@nuobit.com>
+     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl) -->
+<odoo>
+    <record id="aeat_map_special_prorrate_year_view_form" model="ir.ui.view">
+        <field name="name">aeat.map.special.prorate.year.view.form</field>
+        <field name="model">aeat.map.special.prorrate.year</field>
+        <field name="arch" type="xml">
+            <form string="Aeat VAT special prorate map">
+                <header>
+                    <button
+                        name="compute_prorate"
+                        type="object"
+                        string="Compute"
+                        invisible="state != 'temporary'"
+                        class="oe_highlight"
+                    />
+                    <button
+                        name="close_prorate"
+                        type="object"
+                        string="Close"
+                        invisible="state != 'finale'"
+                        class="oe_highlight"
+                    />
+                    <button
+                        name="compute_prorate"
+                        type="object"
+                        string="Recompute"
+                        invisible="state != 'finale'"
+                    />
+                    <button
+                        name="set_temporary"
+                        type="object"
+                        string="Set to Temporary"
+                        invisible="state != 'finale'"
+                    />
+                    <field name="state" widget="statusbar" clickable="False" />
+                </header>
+                <sheet>
+                    <group>
+                        <group>
+                            <field name="year" />
+                            <field name="company_id" />
+                        </group>
+                        <group>
+                            <field name="tax_percentage" />
+                            <field
+                                name="tax_final_percentage_aux"
+                                invisible="state != 'finale'"
+                            />
+                            <field
+                                name="tax_final_percentage"
+                                invisible="state != 'closed'"
+                            />
+                        </group>
+                    </group>
+                </sheet>
+            </form>
+        </field>
+    </record>
+
+    <record id="aeat_map_special_prorrate_year_view_tree" model="ir.ui.view">
+        <field name="name">aeat.map.special.prorate.year.view.list</field>
+        <field name="model">aeat.map.special.prorrate.year</field>
+        <field name="arch" type="xml">
+            <list>
+                <field name="year" />
+                <field name="tax_percentage" />
+                <field name="tax_final_percentage" />
+                <field name="state" />
+                <field name="company_id" />
+            </list>
+        </field>
+    </record>
+
+    <record id="action_aeat_map_special_prorrate_year" model="ir.actions.act_window">
+        <field name="name">Aeat VAT special prorate map</field>
+        <field name="res_model">aeat.map.special.prorrate.year</field>
+        <field name="view_mode">list,form</field>
+    </record>
+
+    <menuitem
+        id="menu_aeat_map_special_prorrate_year"
+        parent="l10n_es_aeat.menu_l10n_es_aeat_config"
+        action="action_aeat_map_special_prorrate_year"
+        name="Aeat VAT special prorate map"
+    />
+</odoo>
diff --git a/l10n_es_aeat_vat_special_prorrate/views/res_company_view.xml b/l10n_es_aeat_vat_special_prorrate/views/res_company_view.xml
new file mode 100644
index 000000000..1b4b0aada
--- /dev/null
+++ b/l10n_es_aeat_vat_special_prorrate/views/res_company_view.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!-- Copyright NuoBiT Solutions SL - Kilian Niubo <kniubo@nuobit.com>
+     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
+ -->
+<odoo>
+    <record id="view_company_aeat_form" model="ir.ui.view">
+        <field name="name">res.company.aeat.form</field>
+        <field name="model">res.company</field>
+        <field name="inherit_id" ref="base.view_company_form" />
+        <field name="arch" type="xml">
+            <notebook position="inside">
+                <page name="Prorate" string="Prorate">
+                    <group>
+                        <group name="Prorate">
+                            <field name="l10n_es_prorate_enabled" />
+                        </group>
+                    </group>
+                </page>
+            </notebook>
+        </field>
+    </record>
+</odoo>
diff --git a/test-requirements.txt b/test-requirements.txt
new file mode 100644
index 000000000..8703a2054
--- /dev/null
+++ b/test-requirements.txt
@@ -0,0 +1 @@
+odoo-addon-l10n_es_special_prorate@git+https://github.com/nuobit/odoo-addons.git@refs/pull/800/head#subdirectory=l10n_es_special_prorate