Changes to the CT600 form to include the new Northern Ireland supplementary pages.

As you may or may not know, HMRC have incorporated changes to the CT600 to cater for the Northern Ireland Assembly setting a Northern Ireland rate of Corporation Tax to apply to certain trading income.

These changes were made in preparation for the rate of tax changing in April 2018. This however, was not the case and the rate of tax remained the same as the UK. Therefore, there are extra boxes available on the main CT600 as well as the new Northern Ireland supplementary pages that HMRC’s online platform does not currently cater for. The earliest date from which a Northern Ireland rate of Corporation Tax could be effective is now 1 April 2019.

As the rate has not changed, details of Northern Ireland profits etc are not required for submission (nor will they be able to be successfully filed online). Currently, if you did want to include this information, you will need to:

1. File the return online without the Northern Ireland information and then amend the return to contain the information post submission.
2. Check whether HMRC would be happy to defer the submission until their online platform caters for this information to be filed online.
3. Paper file. We recommend contacting the corporation tax helpline first to ensure that they would accept this by paper. Corporation Tax returns have required online submissions since the version 3 form came out (01/04/2015).

HMRC's current guidance is available via their website. This will be able to provide you with any additional information that you may need.