diff --git a/src/Altinn.App.Api/Controllers/InstancesController.cs b/src/Altinn.App.Api/Controllers/InstancesController.cs
index ee9eb882a..b2ab1c337 100644
--- a/src/Altinn.App.Api/Controllers/InstancesController.cs
+++ b/src/Altinn.App.Api/Controllers/InstancesController.cs
@@ -438,7 +438,7 @@ await instance.WithOnlyAccessibleDataElements(_dataElementAccessChecker),
     /// </summary>
     /// <param name="org">unique identifier of the organisation responsible for the app</param>
     /// <param name="app">application identifier which is unique within an organisation</param>
-    /// <param name="instansiationInstance">instansiation information</param>
+    /// <param name="InstantiationInstance">instansiation information</param>
     /// <param name="language">The currently active user language</param>
     /// <returns>The new instance</returns>
     [HttpPost("create")]
@@ -450,7 +450,7 @@ await instance.WithOnlyAccessibleDataElements(_dataElementAccessChecker),
     public async Task<ActionResult<InstanceResponse>> PostSimplified(
         [FromRoute] string org,
         [FromRoute] string app,
-        [FromBody] InstansiationInstance instansiationInstance,
+        [FromBody] InstantiationInstance InstantiationInstance,
         [FromQuery] string? language = null
     )
     {
@@ -464,7 +464,7 @@ public async Task<ActionResult<InstanceResponse>> PostSimplified(
             return BadRequest("The path parameter 'app' cannot be empty");
         }
 
-        bool isCopyRequest = !string.IsNullOrEmpty(instansiationInstance.SourceInstanceId);
+        bool isCopyRequest = !string.IsNullOrEmpty(InstantiationInstance.SourceInstanceId);
 
         ApplicationMetadata application = await _appMetadata.GetApplicationMetadata();
         if (VerifyInstantiationPermissions(application, org, app, isCopy: isCopyRequest) is { } verificationResult)
@@ -479,7 +479,7 @@ public async Task<ActionResult<InstanceResponse>> PostSimplified(
             );
         }
 
-        InstanceOwner lookup = instansiationInstance.InstanceOwner;
+        InstanceOwner lookup = InstantiationInstance.InstanceOwner;
 
         if (
             lookup == null
@@ -494,8 +494,8 @@ public async Task<ActionResult<InstanceResponse>> PostSimplified(
         Party party;
         try
         {
-            party = await LookupParty(instansiationInstance.InstanceOwner) ?? throw new Exception("Unknown party");
-            instansiationInstance.InstanceOwner = InstantiationHelper.PartyToInstanceOwner(party);
+            party = await LookupParty(InstantiationInstance.InstanceOwner) ?? throw new Exception("Unknown party");
+            InstantiationInstance.InstanceOwner = InstantiationHelper.PartyToInstanceOwner(party);
         }
         catch (Exception partyLookupException)
         {
@@ -513,7 +513,7 @@ public async Task<ActionResult<InstanceResponse>> PostSimplified(
         if (
             isCopyRequest
             && party.PartyId.ToString(CultureInfo.InvariantCulture)
-                != instansiationInstance.SourceInstanceId.Split("/")[0]
+                != InstantiationInstance.SourceInstanceId.Split("/")[0]
         )
         {
             return BadRequest("It is not possible to copy instances between instance owners.");
@@ -536,9 +536,9 @@ public async Task<ActionResult<InstanceResponse>> PostSimplified(
 
         Instance instanceTemplate = new()
         {
-            InstanceOwner = instansiationInstance.InstanceOwner,
-            VisibleAfter = instansiationInstance.VisibleAfter,
-            DueBefore = instansiationInstance.DueBefore,
+            InstanceOwner = InstantiationInstance.InstanceOwner,
+            VisibleAfter = InstantiationInstance.VisibleAfter,
+            DueBefore = InstantiationInstance.DueBefore,
             Org = application.Org,
         };
 
@@ -564,7 +564,7 @@ public async Task<ActionResult<InstanceResponse>> PostSimplified(
             {
                 Instance = instanceTemplate,
                 User = User,
-                Prefill = instansiationInstance.Prefill,
+                Prefill = InstantiationInstance.Prefill,
             };
 
             processResult = await _processEngine.GenerateProcessStartEvents(request);
@@ -573,7 +573,7 @@ public async Task<ActionResult<InstanceResponse>> PostSimplified(
 
             if (isCopyRequest)
             {
-                string[] sourceSplit = instansiationInstance.SourceInstanceId.Split("/");
+                string[] sourceSplit = InstantiationInstance.SourceInstanceId.Split("/");
                 Guid sourceInstanceGuid = Guid.Parse(sourceSplit[1]);
 
                 try
@@ -604,7 +604,7 @@ public async Task<ActionResult<InstanceResponse>> PostSimplified(
             instance = await _instanceClient.GetInstance(instance);
             await _processEngine.HandleEventsAndUpdateStorage(
                 instance,
-                instansiationInstance.Prefill,
+                InstantiationInstance.Prefill,
                 processResult.ProcessStateChange?.Events
             );
         }
diff --git a/src/Altinn.App.Api/Models/InstansiationInstance.cs b/src/Altinn.App.Api/Models/InstansiationInstance.cs
index 12ff981fa..b7b8abd83 100644
--- a/src/Altinn.App.Api/Models/InstansiationInstance.cs
+++ b/src/Altinn.App.Api/Models/InstansiationInstance.cs
@@ -7,7 +7,7 @@ namespace Altinn.App.Api.Models;
 /// <summary>
 /// Specialized model for instansiation of instances
 /// </summary>
-public class InstansiationInstance
+public class InstantiationInstance
 {
     /// <summary>
     /// Gets or sets the instance owner information.
diff --git a/test/Altinn.App.Api.Tests/OpenApi/OpenApiSpecChangeDetection.SaveJsonSwagger.verified.json b/test/Altinn.App.Api.Tests/OpenApi/OpenApiSpecChangeDetection.SaveJsonSwagger.verified.json
index e5c3e528c..9d8178c43 100644
--- a/test/Altinn.App.Api.Tests/OpenApi/OpenApiSpecChangeDetection.SaveJsonSwagger.verified.json
+++ b/test/Altinn.App.Api.Tests/OpenApi/OpenApiSpecChangeDetection.SaveJsonSwagger.verified.json
@@ -2702,17 +2702,17 @@
           "content": {
             "application/json": {
               "schema": {
-                "$ref": "#/components/schemas/InstansiationInstance"
+                "$ref": "#/components/schemas/InstantiationInstance"
               }
             },
             "text/json": {
               "schema": {
-                "$ref": "#/components/schemas/InstansiationInstance"
+                "$ref": "#/components/schemas/InstantiationInstance"
               }
             },
             "application/*+json": {
               "schema": {
-                "$ref": "#/components/schemas/InstansiationInstance"
+                "$ref": "#/components/schemas/InstantiationInstance"
               }
             }
           }
@@ -8334,7 +8334,7 @@
         },
         "additionalProperties": false
       },
-      "InstansiationInstance": {
+      "InstantiationInstance": {
         "type": "object",
         "properties": {
           "instanceOwner": {
diff --git a/test/Altinn.App.Api.Tests/PublicApiTests.PublicApi_ShouldNotChange_Unintentionally.verified.txt b/test/Altinn.App.Api.Tests/PublicApiTests.PublicApi_ShouldNotChange_Unintentionally.verified.txt
index 6c4a1a9a0..8f4436ad7 100644
--- a/test/Altinn.App.Api.Tests/PublicApiTests.PublicApi_ShouldNotChange_Unintentionally.verified.txt
+++ b/test/Altinn.App.Api.Tests/PublicApiTests.PublicApi_ShouldNotChange_Unintentionally.verified.txt
@@ -327,7 +327,7 @@ namespace Altinn.App.Api.Controllers
         [Microsoft.AspNetCore.Mvc.ProducesResponseType(400)]
         [Microsoft.AspNetCore.Mvc.ProducesResponseType(typeof(Altinn.App.Api.Models.InstanceResponse), 201)]
         [Microsoft.AspNetCore.Mvc.RequestSizeLimit(2097152000)]
-        public System.Threading.Tasks.Task<Microsoft.AspNetCore.Mvc.ActionResult<Altinn.App.Api.Models.InstanceResponse>> PostSimplified([Microsoft.AspNetCore.Mvc.FromRoute] string org, [Microsoft.AspNetCore.Mvc.FromRoute] string app, [Microsoft.AspNetCore.Mvc.FromBody] Altinn.App.Api.Models.InstansiationInstance instansiationInstance, [Microsoft.AspNetCore.Mvc.FromQuery] string? language = null) { }
+        public System.Threading.Tasks.Task<Microsoft.AspNetCore.Mvc.ActionResult<Altinn.App.Api.Models.InstanceResponse>> PostSimplified([Microsoft.AspNetCore.Mvc.FromRoute] string org, [Microsoft.AspNetCore.Mvc.FromRoute] string app, [Microsoft.AspNetCore.Mvc.FromBody] Altinn.App.Api.Models.InstantiationInstance InstantiationInstance, [Microsoft.AspNetCore.Mvc.FromQuery] string? language = null) { }
         [Microsoft.AspNetCore.Authorization.Authorize]
         [Microsoft.AspNetCore.Mvc.HttpPut("{instanceOwnerPartyId:int}/{instanceGuid:guid}/substatus")]
         [Microsoft.AspNetCore.Mvc.Produces("application/json", new string[0])]
@@ -1028,9 +1028,9 @@ namespace Altinn.App.Api.Models
         public required System.DateTime? VisibleAfter { get; init; }
         public override string ToString() { }
     }
-    public class InstansiationInstance
+    public class InstantiationInstance
     {
-        public InstansiationInstance() { }
+        public InstantiationInstance() { }
         public System.DateTime? DueBefore { get; set; }
         public Altinn.Platform.Storage.Interface.Models.InstanceOwner InstanceOwner { get; set; }
         public System.Collections.Generic.Dictionary<string, string> Prefill { get; set; }
diff --git a/test/Altinn.App.Integration.Tests/Basic/BasicAppTests.cs b/test/Altinn.App.Integration.Tests/Basic/BasicAppTests.cs
index 0322bb36f..598b3d154 100644
--- a/test/Altinn.App.Integration.Tests/Basic/BasicAppTests.cs
+++ b/test/Altinn.App.Integration.Tests/Basic/BasicAppTests.cs
@@ -99,11 +99,11 @@ TestCase testCase
         {
             TestCase.SimplifiedNoPrefill => await fixture.Instances.PostSimplified(
                 token,
-                new InstansiationInstance { InstanceOwner = new InstanceOwner { PartyId = "501337" } }
+                new InstantiationInstance { InstanceOwner = new InstanceOwner { PartyId = "501337" } }
             ),
             TestCase.SimplifiedWithPrefill => await fixture.Instances.PostSimplified(
                 token,
-                new InstansiationInstance
+                new InstantiationInstance
                 {
                     InstanceOwner = new InstanceOwner { PartyId = "501337" },
                     Prefill = new() { { "property1", "1" }, { "property2", "1" } },
diff --git a/test/Altinn.App.Integration.Tests/PartyTypesAllowed/SubunitOnlyAppTests.cs b/test/Altinn.App.Integration.Tests/PartyTypesAllowed/SubunitOnlyAppTests.cs
index b2f20d1ab..151d24f44 100644
--- a/test/Altinn.App.Integration.Tests/PartyTypesAllowed/SubunitOnlyAppTests.cs
+++ b/test/Altinn.App.Integration.Tests/PartyTypesAllowed/SubunitOnlyAppTests.cs
@@ -23,7 +23,7 @@ public async Task Instantiate(string partyId)
 
         using var response = await fixture.Instances.PostSimplified(
             token,
-            new InstansiationInstance { InstanceOwner = new InstanceOwner { PartyId = partyId } }
+            new InstantiationInstance { InstanceOwner = new InstanceOwner { PartyId = partyId } }
         );
 
         using var data = await response.Read<Instance>();
diff --git a/test/Altinn.App.Integration.Tests/README.md b/test/Altinn.App.Integration.Tests/README.md
index a1eb44b28..a1e331e96 100644
--- a/test/Altinn.App.Integration.Tests/README.md
+++ b/test/Altinn.App.Integration.Tests/README.md
@@ -50,7 +50,7 @@ public class MyIntegrationTests(ITestOutputHelper output) : IAsyncLifetime
 
         using var response = await fixture.Instances.PostSimplified(
             token,
-            new InstansiationInstance { InstanceOwner = new InstanceOwner { PartyId = "501337" } }
+            new InstantiationInstance { InstanceOwner = new InstanceOwner { PartyId = "501337" } }
         );
 
         var readResponse = await response.Read<Instance>();
@@ -147,7 +147,7 @@ The `ApiResponse` pattern provides structured HTTP response handling:
 ```csharp
 using var response = await fixture.Instances.PostSimplified(
     token,
-    new InstansiationInstance { InstanceOwner = new InstanceOwner { PartyId = "501337" } }
+    new InstantiationInstance { InstanceOwner = new InstanceOwner { PartyId = "501337" } }
 );
 
 // Read typed response data
diff --git a/test/Altinn.App.Integration.Tests/_fixture/Operations/AppFixture.Instances.cs b/test/Altinn.App.Integration.Tests/_fixture/Operations/AppFixture.Instances.cs
index 542f17091..319644ece 100644
--- a/test/Altinn.App.Integration.Tests/_fixture/Operations/AppFixture.Instances.cs
+++ b/test/Altinn.App.Integration.Tests/_fixture/Operations/AppFixture.Instances.cs
@@ -24,7 +24,7 @@ internal sealed class InstancesOperations(AppFixture fixture)
     {
         private readonly AppFixture _fixture = fixture;
 
-        public async Task<ApiResponse> PostSimplified(string token, InstansiationInstance instansiation)
+        public async Task<ApiResponse> PostSimplified(string token, InstantiationInstance instansiation)
         {
             var client = _fixture.GetAppClient();
             var endpoint = $"/ttd/{_fixture._app}/instances/create";