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HMRC internal manual

COTAX Manual

Assessing: CTSA assessments: recording a self assessment

This subject is presented as follows.

Normal procedure
Action needed 

Normal procedure

Wherever possible, COTAX records the self assessment automatically when a return is received from the CT Online Service.


Sometimes COTAX cannot record the self assessment automatically. Those cases are entered on EFRL (E-filed Return Work List) with a reason for entry. You must review them and take any action required to record the self assessment on COTAX.

Action needed

COTAX shows the figures from the return in RAMA. You can correct them if needed or record the self assessment as submitted. If you make changes that constitute a correction of the self assessment, COTAX issues a correction notice showing the amended figures. If necessary, you can suppress assessing output. See COM23050 for more information on correcting returns.

Once the self assessment is recorded, COTAX posts the self assessment charge to the company’s AP. Any revenue determination charge for the AP or any period superseded by it is displaced. The company can see that the self assessment has been recorded in its online tax account.

COTAX also calculates whether any credit interest is due and posts it to the record. See COM80000 for more information.

If the assessment you have prepared affects the penalty position on that AP, COTAX gives you the following options for dealing with the penalty at the end of RAMA.

  • Allowing the automatic issue of penalties.
  • Proceeding to function PPEN (Prepare Penalty Determination) to issue or revise the penalty determination.
  • Setting the ‘no penalty required’ indicator.

You should normally select the automatic issue of penalties option.


  • COM100000 onwards for more information on penalties
  • COM23011 for a list of forms relevant to this subject
  • COM23012 for a list of functions to use in particular situations
  • COM23013 for legislation applying to this subject.