Vat not adding up when cross checked

motorbykcourier

Hi Folks,
Firstly I'm based in the UK and use cash accounting for my business.
Am trying to sort my year-end details and was of the opinion all was good with the data within Wave.
My accountant decided to cross-check the vat workings by using the details in General Ledger, adjusting for Debtors and Creditors.
Unfortunately, she found some discrepancies, which having checked my (original) data I can not explain why there should be these differences.
Has anyone else ever had a similar issue or is there something I have missed?
Many thanks in advance

Steve....