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HMRC internal manual

Self Assessment Manual

HM Revenue & Customs
, see all updates

Returns: individuals returns: error and warning messages: individuals

There are two types of computer messages which you may see whilst entering the information from the return during capture using function CAPTURE RETURN. These are prompted by checks carried out by the computer on the information entered.

The two types of message are

  • Error messages
  • Warning messages

Error messages arise following arithmetic and similar checks carried out by the computer.

Warning messages arise to prompt you to check what you have entered in unlikely situations.

There are various ways in which errors and omissions on a return can be handled and system help is available at function, screen, field and error message level throughout function CAPTURE RETURN.

When a figure has been checked you must accept the taxpayer’s figure (SAM121265) without amendment, once you are sure that

  • The figure has been copied correctly
  • The taxpayer has not made an obvious error or mistake
  • If you identify that the customer has made an obvious error and omitted information by checking with information held on our systems, you can correct that information under S9ZB TMA1970. However, in these case you must advise the customer in writing what you have corrected and why. For further information, see the relevant PT Ops Action Guide


Otherwise there is a risk of starting a Check Later enquiry prematurely or by accident.

In all cases you must take care when presented with the error message on boxes 1 and 2 of the Tax Calculation Summary page TCS1 of a Main Tax Return where a difference arises between the taxpayer’s amount and the computer calculated amount. There are a number of points to consider (SAM121512) before making the decision to either accept or repair the taxpayer’s entry.

Note: There are occasions where an error message and a warning message are appropriate to the same box on the return. The error message is displayed first and depending on the action you take to clear the error message you may or may not see the subsequent warning message. You will not see the warning message if you ‘accept’ the taxpayer’s figure to clear the error.

In these circumstances you must remember to carry out the action that you would be prompted to do by the warning message. The box numbers affected on the SA100 are

  • Box 79 on the Self-employment (full) page SEF 4
  • Box 34 on the Self-employment (short) page SES 2
  • Box 23 on both the Partnership (full) page PF 2 and the Partnership (short) page PS 2
  • Box 17 on the UK property page UKP 1

These boxes refer to pension contributions or losses that are to be carried back. The warning message advises you that the relief needs to be calculated in Revenue calculation cases and entered in the appropriate box during capture.

In dealing with errors always consider the individual circumstances of the case. Avoid unnecessary communication and use your judgement and experience.

If you need to contact the person who submitted the return to clarify minor points and to avoid delaying capture of the return use the telephone or exceptionally if you have been given permission by your manager, write a letter. You must make it clear that the query

  • Is designed to allow you to process the return on the basis of the figures supplied
  • Does no more than clarify unclear handwriting or arithmetic

In all other cases or if in doubt you should accept the taxpayer’s figure.