Good day, kgabo-hummingbir.

Processing VAT adjustment in QuickBooks Online is quick and easy, Here are the steps to complete the process.

1. Click Taxes on the left panel.
2. Go to the Returns tab.
3. Choose the tax or VAT you need to adjust and tap Prepare return.
   
4. From the Prepare VAT/GST return screen, click on Adjust.
   
5. Enter the necessary information.
6. Hit Save.
   

To know more about how VAT works in QuickBooks Online, check out the following resources below. Also, these will provide you ways on how to manage and track your adjustments in QuickBooks Online:

VAT Feature Update FAQ.

Track sales tax adjustments.

After trying the steps above, let me know how it goes by leaving a comment below. I’ll be here to keep helping. Have a good one.