VATREC13050 - Credit and Debit notes: What if the conditions for the issue of a valid credit note are not met?
As explained in VATREC13010 and VATREC13020, the VAT liability has to be determined by reference to the true tax, irrespective of the issue or receipt of credit notes. Credit notes are only prima facie evidence of a change in the underlying supply and, if the parties are in dispute, it is that underlying position which will determine the tax due.