Hi @joesay,
Yes, this is possible. Let me point you in the right direction where you can get support for this query.
To unfile your last month's submitted VAT return, you'll have to contact our Technical Support team for assistance.
Here's how:
- Log in to your QuickBooks Online company.
- Click the Help menu.
- Select Contact us.
In case you need to adjust your VAT liability, you can open the link I provided. Here you'll find the steps on how you can adjust the VAT on boxes 1, 2 and 4, as well as 6, 7, 8, and 9. You'll also see some screenshots for your reference.
Do you have any other questions in mind? Feel free to post it in the comments below, and I'll get back to you.