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HMRC internal manual

VAT Assessments and Error Correction

How to assess and correct: Assessment procedures: VAT646 Officers assessment abort message

This is a VALID input document which is used by the local office to notify the computer system that an assessment or error correction should be aborted and not updated to the trader’s file.

Upon receipt of the VAT655 or VAT657, the VALID post input control seat should check the information against the input documents, VAT641 or VAT642. If the information is incorrect, a VAT646 should be completed.

If the outputs are incorrect you should take the following action

  • clearly mark both copies “IN ERROR DO NOT ISSUE”,
  • abort the assessment or voluntary disclosure using the VAT646,
  • scan both copies of the outputs into the trader’s electronic folder, and
  • recommence VAT641 or VAT642 action where appropriate.

Completion of the VAT 646

Please bear the following in mind when completing the form.

Registration number

This is the trader’s VAT registration number.

OA Reference

This is the reference number of the officer’s assessment or error correction to be aborted. This number appears on both copies of the output documents and can also be obtained by looking on the VISION computer system.


This form requires countersignature which should be determined by agreed local levels of authority.

VAT 646 Processing

Once you have completed the VAT 646 and it has been countersigned, it should be input via VALID. The information will be transferred to the Mainframe computer and processed overnight.

Before the trader’s file is updated, a number of validation checks are carried out and the document may be output on the D0502 print. If you require further information on the error codes and solutions you should refer to the document VALID Rejection Errors Reported on D0502 Print

If the document is accepted, the assessment or voluntary disclosure will be wiped from the trader’s file.