When you calculate your VAT Return, if required, you can adjust to your final VAT Return figures before you reconcile your VAT Return. For example, to correct a past error that meets HMRC VAT adjustment criteria.
You can use the Adjustments option to make these amendments.
Check the Manual Adjustment control account:
You must first calculate and check your VAT figures for the period. Follow our VAT reconciliation guide for your VAT scheme.
TIP: VAT Adjustments post automatically with the program date. To post an adjustment with a different date, change your program date. In v30.1 and above the adjustment uses the last date of the VAT Return period.

in the Adjustment column.
TIP: To reduce the box value, prefix the figure with the minus sign '-'.
The adjustments apply when you reconcile the VAT Return. If you close the VAT Return without reconciling, the adjustments don't save. You'll need to post them again after calculating the VAT Return.
When you transfer the VAT from the Sales and Purchase Tax Control Account to the VAT Liability nominal code, use the VAT Transfer Wizard.
If you post a manual VAT transfer, use the calculated figures, not the figures after the adjustments. This is because the adjustment journal posts automatically to VAT Liability.
VAT Adjustments don't affect the Sales or Purchase Tax control accounts. If your adjustment changes box 5, a journal posts between the VAT liability nominal code 2202 and Manual Adjustments nominal code 2204.
After reconciling your VAT return, you can journal any associated balance on 2204 to an appropriate nominal code. If you're unsure about which code to use, refer to your accountant.