If you discover mistakes in a saved VAT return before you have submitted it to HMRC:
1.Select the return in the VAT Returns window (VAT button on the main toolbar) and click on the Delete caption
2.Enter any missing transactions, or delete/edit existing ones by right mouse clicking on the transaction in any report
3.Create and save the VAT return again
If you discover mistakes in a submitted VAT return:
1.Enter any missing transactions
2.If a transaction was incorrectly entered, right mouse click on it in any report and choose Make Reversal Copy (or Raise Credit Note for an invoice) from the pop-up menu. The transaction should then be re-entered correctly. This process is necessary because you cannot directly edit transactions in a saved VAT return
3.Reversals and corrections should normally be dated within the VAT period in which the reversal/correction transactions fall. However, should you for any reason need to backdate reversals and corrections, these will still be picked up in the current VAT return as they have not been included in a previous return.
4.Depending on the amount of the corrections and the HMRC regulations ruling at the time, you can allow the adjustments to be included in your next VAT return, or you may have to declare the corrections on a VAT 652 form. For your obligations in this respect please refer to HMRC Notice 700/45.