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HMRC internal manual

COTAX Manual

Returns / notices: return handling: dealing with returns received

Companies must submit their returns using the Corporation Tax Online Service for any AP ending on or after 1 April 2010. There are some exemptions to the obligation to file electronically. See COM132001 for details.

COTAX captures the return details and records the self assessment automatically whenever possible. Where it is unable to do so, it puts the case onto a work list, usually EFRL (E-Filed Return List).

It is important to review cases on EFRL quickly to make sure all self assessments are recorded as soon as possible.

You sometimes have to manually log and capture a return because:

  • COTAX cannot deal with the case automatically even after you have changed the AP structure or taken other manual action
  • you have accepted a paper return for a company that is not obliged to submit its return online.

You should log a paper return, capture it and record the self assessment on the day of receipt.

Because CT Self Assessment is a ‘process now, check later’ regime, you should aim to process a return whenever possible. We can subsequently risk assess and use our correction and enquiry powers to deal with any returns which warrant intervention.

There is no validation to prevent an agent or company submitting the CT600, accounts and computations for a company using the UTR for a different company and we know this does happen. You need to be aware of this and follow the guidance at COM131041 if you find such a return.

You must only unlog a return as unacceptable in exceptional circumstances. If you do have to reject a return, you should use function NOTE (Case Notes) and say that you received a return and why you rejected it.


  • COM132011 for a list of forms relevant to this subject
  • COM132021 for a list of functions to use in particular situations.