diff --git a/README.md b/README.md
index 0edf29c..baaed2e 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,30 @@ end
 # will produce => "2011HOUSE00001", "2011HOUSE00002"...
 ```
 
+It's possible to pass :scope_by option as a simple method, Proc.new or lambda
+
+Ex:
+```ruby
+# :manufacturer should be a Car's instance method(like an ActiveRecord column)
+class Car < ActiveRecord::Base
+    protokoll :code, :scope_by => :manufacturer
+end
+# will scope Cars by manufacturers, for example "Ford", "Chevrolet"
+
+# :manufacturer and :year should be Car's instance methods(like ActiveRecord columns)
+class Car < ActiveRecord::Base
+    protokoll :code, :scope_by => lambda { |o| "#{o.manufacturer}-#{o.year}" }
+end
+# will scope Cars by for example "Ford-2016"
+
+# :manufacturer and :year should be Car's instance methods(like ActiveRecord columns)
+class Car < ActiveRecord::Base
+    protokoll :code, :scope_by => Proc.new{ "#{manufacturer}-#{model}" }
+end
+# will scope Cars by for example "Ford-Mustang", "Chevrolet-Camaro"
+```
+
+
 ## reserve_number!
 
    object.reserve_number!
@@ -116,6 +140,10 @@ Run the generator
 
     rails g protokoll:migration
 
+Optional: If scope_by will be used run next generator as well
+
+    rails g protokoll:migration:scope_by
+
 and migrate your database
 
     rake db:migrate
diff --git a/lib/generators/protokoll/migration/scope_by_generator.rb b/lib/generators/protokoll/migration/scope_by_generator.rb
new file mode 100644
index 0000000..679d4e3
--- /dev/null
+++ b/lib/generators/protokoll/migration/scope_by_generator.rb
@@ -0,0 +1,26 @@
+require 'rails/generators'
+
+module Protokoll
+  module Generators
+    module Migration
+      class ScopeByGenerator < ::Rails::Generators::Base
+
+        include Rails::Generators::Migration
+
+        desc "Generate protokoll's scope_by migration"
+        def create_migration_file
+          migration_name = "add_scope_by_to_custom_auto_increments.rb"
+          migration_template migration_name, File.join('db', 'migrate', migration_name)
+        end
+
+        def self.source_root
+          @source_root ||= File.expand_path(File.join(File.dirname(__FILE__), 'templates'))
+        end
+
+        def self.next_migration_number(path)
+          Time.now.utc.strftime("%Y%m%d%H%M%S")
+        end
+      end
+    end
+  end
+end
diff --git a/lib/generators/protokoll/migration/templates/add_scope_by_to_custom_auto_increments.rb b/lib/generators/protokoll/migration/templates/add_scope_by_to_custom_auto_increments.rb
new file mode 100644
index 0000000..d927195
--- /dev/null
+++ b/lib/generators/protokoll/migration/templates/add_scope_by_to_custom_auto_increments.rb
@@ -0,0 +1,12 @@
+class AddScopeByToCustomAutoIncrements < ActiveRecord::Migration
+  def up
+    add_column :custom_auto_increments, :counter_model_scope, :string
+    add_index :custom_auto_increments, [:counter_model_name, :counter_model_scope],
+              :unique => true, :name => :counter_model_name_scope
+  end
+
+  def down
+    remove_index :custom_auto_increments, name: :counter_model_name_scope
+    remove_column :custom_auto_increments, :counter_model_scope, :string
+  end
+end
diff --git a/lib/protokoll/counter.rb b/lib/protokoll/counter.rb
index 27818f7..8c7f1d1 100644
--- a/lib/protokoll/counter.rb
+++ b/lib/protokoll/counter.rb
@@ -3,7 +3,7 @@
 module Protokoll
   class Counter
     def self.next(object, options)
-      element = Models::CustomAutoIncrement.find_or_create_by(counter_model_name: object.class.to_s.underscore)
+      element = Models::CustomAutoIncrement.find_or_create_by(build_attrs(object, options))
 
       element.counter = options[:start] if outdated?(element, options) || element.counter == 0
       element.counter += 1
@@ -18,6 +18,17 @@ def self.next(object, options)
 
     private
 
+    def self.build_attrs(object, options)
+      attrs = {counter_model_name: object.class.to_s.underscore}
+      return attrs unless options[:scope_by]
+
+      scope_by =  options[:scope_by].respond_to?(:call) ?
+                  object.instance_eval(&options[:scope_by]) :
+                  object.send(options[:scope_by])
+
+      attrs.merge(counter_model_scope: scope_by)
+    end
+
     def self.outdated?(record, options)
       Time.now.utc.strftime(update_event(options)).to_i > record.updated_at.strftime(update_event(options)).to_i
     end
diff --git a/lib/protokoll/protokoll.rb b/lib/protokoll/protokoll.rb
index b73dbdc..2369c69 100644
--- a/lib/protokoll/protokoll.rb
+++ b/lib/protokoll/protokoll.rb
@@ -14,7 +14,8 @@ def protokoll(column, _options = {})
       options = { :pattern       => "%Y%m#####",
                   :number_symbol => "#",
                   :column        => column,
-                  :start         => 0 }
+                  :start         => 0,
+                  :scope_by      => nil }
 
       options.merge!(_options)
       raise ArgumentError.new("pattern can't be nil!") if options[:pattern].nil?
diff --git a/test/dummy/db/migrate/20110923024431_create_protocols.rb b/test/dummy/db/migrate/20110923024431_create_protocols.rb
index d864728..2cf5582 100644
--- a/test/dummy/db/migrate/20110923024431_create_protocols.rb
+++ b/test/dummy/db/migrate/20110923024431_create_protocols.rb
@@ -2,6 +2,8 @@ class CreateProtocols < ActiveRecord::Migration
   def change
     create_table :protocols do |t|
       t.string :number
+      t.string :context
+      t.string :context_2
 
       t.timestamps
     end
diff --git a/test/dummy/db/migrate/20120222164124_create_custom_auto_increments.rb b/test/dummy/db/migrate/20120222164124_create_custom_auto_increments.rb
index 93fba87..b559411 100644
--- a/test/dummy/db/migrate/20120222164124_create_custom_auto_increments.rb
+++ b/test/dummy/db/migrate/20120222164124_create_custom_auto_increments.rb
@@ -1,7 +1,7 @@
 class CreateCustomAutoIncrements < ActiveRecord::Migration
   def up
     create_table :custom_auto_increments, :force => true do |t|
-      t.string  :counter_model_name
+      t.string :counter_model_name
       t.integer :counter, :default => 0
       t.timestamps
     end
diff --git a/test/dummy/db/migrate/20160310030821_add_scope_by_to_custom_auto_increments.rb b/test/dummy/db/migrate/20160310030821_add_scope_by_to_custom_auto_increments.rb
new file mode 100644
index 0000000..d927195
--- /dev/null
+++ b/test/dummy/db/migrate/20160310030821_add_scope_by_to_custom_auto_increments.rb
@@ -0,0 +1,12 @@
+class AddScopeByToCustomAutoIncrements < ActiveRecord::Migration
+  def up
+    add_column :custom_auto_increments, :counter_model_scope, :string
+    add_index :custom_auto_increments, [:counter_model_name, :counter_model_scope],
+              :unique => true, :name => :counter_model_name_scope
+  end
+
+  def down
+    remove_index :custom_auto_increments, name: :counter_model_name_scope
+    remove_column :custom_auto_increments, :counter_model_scope, :string
+  end
+end
diff --git a/test/dummy/db/schema.rb b/test/dummy/db/schema.rb
index fe11cc8..c40daaa 100644
--- a/test/dummy/db/schema.rb
+++ b/test/dummy/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20120222164124) do
+ActiveRecord::Schema.define(version: 20160310030821) do
 
   create_table "calls", force: :cascade do |t|
     t.string   "number"
@@ -21,15 +21,19 @@
 
   create_table "custom_auto_increments", force: :cascade do |t|
     t.string   "counter_model_name"
-    t.integer  "counter",            default: 0
+    t.integer  "counter",             default: 0
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.string   "counter_model_scope"
   end
 
+  add_index "custom_auto_increments", ["counter_model_name", "counter_model_scope"], name: "counter_model_name_scope", unique: true
   add_index "custom_auto_increments", ["counter_model_name"], name: "index_custom_auto_increments_on_counter_model_name"
 
   create_table "protocols", force: :cascade do |t|
     t.string   "number"
+    t.string   "context"
+    t.string   "context_2"
     t.datetime "created_at"
     t.datetime "updated_at"
   end
diff --git a/test/protokoll_test.rb b/test/protokoll_test.rb
index 5290d16..858674d 100644
--- a/test/protokoll_test.rb
+++ b/test/protokoll_test.rb
@@ -388,6 +388,53 @@ class Protocol < ActiveRecord::Base
     assert_equal "2011092601", protocol3.number
   end
 
+  test "counter should consider instance method scope given" do
+    class Protocol < ActiveRecord::Base
+      protokoll :number, :scope_by => :context
+    end
+
+    protocol1 = Protocol.create! context: 'scenario_1'
+    protocol2 = Protocol.create! context: 'scenario_2'
+    protocol3 = Protocol.create! context: 'scenario_1'
+
+    assert_equal "20110900001", protocol1.number
+    assert_equal "20110900001", protocol2.number
+    assert_equal "20110900002", protocol3.number
+  end
+
+  test "counter should consider Proc scope given" do
+    class Protocol < ActiveRecord::Base
+      protokoll :number, :scope_by => Proc.new { "#{context}-#{context_2}" }
+    end
+
+    protocol1 = Protocol.create! context: 'scenario_1', context_2: 'case1'
+    protocol2 = Protocol.create! context: 'scenario_2', context_2: 'case1'
+    protocol3 = Protocol.create! context: 'scenario_1', context_2: 'case1'
+    protocol4 = Protocol.create! context: 'scenario_1', context_2: 'case2'
+
+    assert_equal "20110900001", protocol1.number
+    assert_equal "20110900001", protocol2.number
+    assert_equal "20110900002", protocol3.number
+    assert_equal "20110900001", protocol4.number
+  end
+
+  test "counter should consider lambda scope given" do
+    class Protocol < ActiveRecord::Base
+      protokoll :number, :scope_by => lambda { |o| "#{o.context}-#{o.context_2}" }
+    end
+
+    protocol1 = Protocol.create! context: 'scenario_1', context_2: 'case1'
+    protocol2 = Protocol.create! context: 'scenario_2', context_2: 'case1'
+    protocol3 = Protocol.create! context: 'scenario_1', context_2: 'case1'
+    protocol4 = Protocol.create! context: 'scenario_1', context_2: 'case2'
+
+    assert_equal "20110900001", protocol1.number
+    assert_equal "20110900001", protocol2.number
+    assert_equal "20110900002", protocol3.number
+    assert_equal "20110900001", protocol4.number
+  end
+
+
   test "rejects empty patterns" do
 
     assert_raise ArgumentError do