Beta This part of GOV.UK is being rebuilt – find out what this means

HMRC internal manual

COTAX Manual

HM Revenue & Customs
, see all updates

Returns / notices: notices and returns: unsatisfactory returns

This subject is presented as follows.

Borderline cases
Estimated figures 


A company tax return must satisfy the requirements of the notice to deliver. The Corporation Tax Online Service carries out validation on the items submitted to ensure that most company tax returns submitted are complete.

In general, HM Revenue & Customs takes the view that if the return includes accounts and computations in iXBRL format where required, we will accept it as a valid company tax return unless and until close scrutiny as part of a general compliance review shows that it is not. See COM130060 for further information.


It should be exceptional for an electronically submitted return to be considered unsatisfactory and the fact will not normally be established until a compliance review is carried out. If the company has not made a return that complies with the requirements of a notice to deliver, it may be liable to penalties for failure to make a return.

A company may also deliver a return that meets the requirements of a notice to deliver but is incorrect. In such a case, it has satisfied its obligation to make a return, but may be liable to penalties for making an incorrect return. For more information about incorrect returns, see the Enquiry Manual.

Borderline cases

CT Self Assessment is a ‘process now, check later’ regime and HM Revenue & Customs has made the transition to mandatory online filing as easy as possible for companies. We therefore reject as unsatisfactory as few returns as possible. Instead, you should contact agents and companies to draw their attention to errors where they have genuinely tried to comply with mandation. They will then be able to submit acceptable returns in future. For more guidance, refer to COM130062.

In general terms, failure to include items, or providing them in the wrong format is a technical issue and should be looked at as part of the risk assessment of the return; it is not something that should lead to ‘rejection’ as part of processing the return. Whenever possible, you should give the company or agent the opportunity to explain themselves and to put right any omission.

Estimated figures

In Dunk v General Commissioners of Income Tax for Havant and CIR 51 TC 519 the taxpayer claimed that he could not make a return because he did not possess all the relevant information. The Commissioners decided that the obligation is to make a return that is to the best of the taxpayer’s knowledge complete and correct.

If the company uses all proper sources of information but finds that the best of its knowledge is unreliable, it can indicate that there is an estimated figure on the return. You would expect an explanation to be included as a note or an attached PDF. However, it would be identified as part of a compliance review and does not need to be considered as part of any manual intervention required to process the return onto COTAX.

When a company can later replace an estimate with an accurate figure, it should do so at the earliest opportunity. If it does that, Para 20 Sch 18 FA 1998 should remove the risk of a penalty arising under the appropriate penalty legislation, provided that the original return was not submitted fraudulently or negligently. For further information about penalties see COM100000 onwards.


  • COM132000 about the initial clerical review of a return
  • COM130011 for a list of forms relevant to this subject
  • COM130012 for legislation applying to this subject.