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HMRC internal manual

COTAX Manual

CT Pay and File: assessments: invalid assessments

When you have issued an assessment, you cannot delete it from the COTAX record.

Consequently, if you have issued an assessment that is invalid, you must reduce it to NIL.COTAX then holds details of both the invalid assessment and the NIL amendment.

If you later used COTAX to make a new valid assessment, it would incorrectly show as a further assessment, both on the COTAX record and on the output to the company and / or agent.

In these circumstances you must

  • Issue the assessment manually
  • Record the manual issue on the COTAX record


  • Make a prominent note on the record using Function NOTE (Case Notes)

For a list of functions to use in particular situations, see COM151011.