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HMRC internal manual

VAT Assessments and Error Correction

Error correction for VAT returns: Time limits: Periods after deregistration

However, separate notification of errors on previously submitted tax returns can still be made for accounting periods ending on or before, the date of deregistration. For guidance on making separate notification, see VAEC7120.

Where the date of deregistration is amended to a later date, and an error correction is subsequently made relating to the extended period, you should establish whether the amended deregistration date is correct.