diff --git a/app/models/ticket/number/date.rb b/app/models/ticket/number/date.rb
index 5dc97969c..e32b53874 100644
--- a/app/models/ticket/number/date.rb
+++ b/app/models/ticket/number/date.rb
@@ -81,6 +81,10 @@ module Ticket::Number::Date
     ticket_hook_divider = Setting.get('ticket_hook_divider') || ''
     ticket              = nil
 
+    if Setting.get('ticket_number_ignore_system_id') == true
+      system_id = ''
+    end
+
     # probe format
     string.scan(/#{Regexp.quote(ticket_hook)}#{Regexp.quote(ticket_hook_divider)}(\d{4,10}#{system_id}\d{2,40})/i) do
       ticket = Ticket.find_by(number: $1)
diff --git a/app/models/ticket/number/increment.rb b/app/models/ticket/number/increment.rb
index 68da1f450..0e5b0d9a7 100644
--- a/app/models/ticket/number/increment.rb
+++ b/app/models/ticket/number/increment.rb
@@ -78,6 +78,10 @@ module Ticket::Number::Increment
     ticket_hook_divider = Setting.get('ticket_hook_divider') || ''
     ticket              = nil
 
+    if Setting.get('ticket_number_ignore_system_id') == true
+      system_id = ''
+    end
+
     # probe format
     string.scan(/#{Regexp.quote(ticket_hook)}#{Regexp.quote(ticket_hook_divider)}(#{system_id}\d{2,48})/i) do
       ticket = Ticket.find_by(number: $1)
diff --git a/db/migrate/20180116000001_setting_ticket_number_ignore_system_id_support.rb b/db/migrate/20180116000001_setting_ticket_number_ignore_system_id_support.rb
new file mode 100644
index 000000000..d696691ca
--- /dev/null
+++ b/db/migrate/20180116000001_setting_ticket_number_ignore_system_id_support.rb
@@ -0,0 +1,37 @@
+class SettingTicketNumberIgnoreSystemIdSupport < ActiveRecord::Migration[4.2]
+  def up
+
+    # return if it's a new setup
+    return if !Setting.find_by(name: 'system_init_done')
+
+    Setting.create_if_not_exists(
+      title: 'Ticket Number ignore system_id',
+      name: 'ticket_number_ignore_system_id',
+      area: 'Ticket::Core',
+      description: '-',
+      options: {
+        form: [
+          {
+            display: 'Ignore system_id',
+            null: true,
+            name: 'ticket_number_ignore_system_id',
+            tag: 'boolean',
+            options: {
+              true  => 'yes',
+              false => 'no',
+            },
+          },
+        ],
+      },
+      state: {
+        ticket_number_ignore_system_id: false
+      },
+      preferences: {
+        permission: ['admin.ticket'],
+        hidden: true,
+      },
+      frontend: false
+    )
+  end
+
+end
diff --git a/db/seeds/settings.rb b/db/seeds/settings.rb
index 6e6f2272e..b6bf3c2a3 100644
--- a/db/seeds/settings.rb
+++ b/db/seeds/settings.rb
@@ -1672,6 +1672,34 @@ Setting.create_if_not_exists(
   },
   frontend: false
 )
+Setting.create_if_not_exists(
+  title: 'Ticket Number ignore system_id',
+  name: 'ticket_number_ignore_system_id',
+  area: 'Ticket::Core',
+  description: '-',
+  options: {
+    form: [
+      {
+        display: 'Ignore system_id',
+        null: true,
+        name: 'ticket_number_ignore_system_id',
+        tag: 'boolean',
+        options: {
+          true  => 'yes',
+          false => 'no',
+        },
+      },
+    ],
+  },
+  state: {
+    ticket_number_ignore_system_id: false
+  },
+  preferences: {
+    permission: ['admin.ticket'],
+    hidden: true,
+  },
+  frontend: false
+)
 
 Setting.create_if_not_exists(
   title: 'Enable Ticket creation',
diff --git a/test/unit/ticket_number_test.rb b/test/unit/ticket_number_test.rb
index a72019bff..d708aee70 100644
--- a/test/unit/ticket_number_test.rb
+++ b/test/unit/ticket_number_test.rb
@@ -58,6 +58,33 @@ class TicketNumberTest < ActiveSupport::TestCase
 
   end
 
+  test 'number check' do
+    Setting.set('ticket_number_increment', { checksum: false, min_size: 5 })
+    ticket = Ticket.create!(
+      title: 'test 1',
+      group: Group.lookup(name: 'Users'),
+      customer_id: 2,
+      state: Ticket::State.lookup(name: 'new'),
+      priority: Ticket::Priority.lookup(name: '2 normal'),
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    subject = ticket.subject_build(ticket.title)
+
+    ticket_check = Ticket::Number.check(subject)
+    assert_equal(ticket.id, ticket_check.id)
+
+    Setting.set('system_id', 999)
+
+    ticket_check = Ticket::Number.check(subject)
+    assert_not(ticket_check)
+
+    Setting.set('ticket_number_ignore_system_id', true)
+
+    ticket_check = Ticket::Number.check(subject)
+    assert_equal(ticket.id, ticket_check.id)
+  end
+
   test 'date' do
     Setting.set('ticket_number', 'Ticket::Number::Date')
     Setting.set('ticket_number_date', { checksum: false })
@@ -103,4 +130,33 @@ class TicketNumberTest < ActiveSupport::TestCase
 
   end
 
+  test 'date check' do
+    Setting.set('ticket_number', 'Ticket::Number::Date')
+    Setting.set('ticket_number_date', { checksum: false })
+
+    ticket = Ticket.create!(
+      title: 'test 1',
+      group: Group.lookup(name: 'Users'),
+      customer_id: 2,
+      state: Ticket::State.lookup(name: 'new'),
+      priority: Ticket::Priority.lookup(name: '2 normal'),
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    subject = ticket.subject_build(ticket.title)
+
+    ticket_check = Ticket::Number.check(subject)
+    assert_equal(ticket.id, ticket_check.id)
+
+    Setting.set('system_id', 999)
+
+    ticket_check = Ticket::Number.check(subject)
+    assert_not(ticket_check)
+
+    Setting.set('ticket_number_ignore_system_id', true)
+
+    ticket_check = Ticket::Number.check(subject)
+    assert_equal(ticket.id, ticket_check.id)
+  end
+
 end