I am afraid, there is still misunderstanding.
I don't need to adjust the filed VAT return - it was correct. However, because of the later bank feed update, one of the income transactions duplicated the same transaction that was already included via file upload. The date on this duplicated transaction belong to the quarter that has already been filed and this is the reason why it's absolutely not possible to remove/delete/void/adjust/undo/cancel this transaction. When I go to Taxes, I can see that Exceptions report includes this duplicated income receipt as if it was previously omitted. But, it wasn't! I don't want this Exceptions report to show me the income that was already taxed. How to remove/adjust it please?.. When I try to do anything with this duplicated income, I get this message:
"Any transactions in a VAT period marked as filed can’t be changed on the Flat Rate Scheme. If you need to update or correct something, just create a new transaction." So, I tried to create another transaction that reverses the duplicated income. This corrects the bank balance, but not the Exceptions report in Taxes. The income still shows up as if it was omitted in the already submitted return - but it wasn't.
