Can I adjust already filed tax returns while using Quickbooks Online in UAE?

Hello there, @sharif-ataya.

Yes, you can adjust an already filed tax return in QuickBooks Online. The filing would need to be undone in order to make corrections. However, this method would apply to accountant users of QuickBooks Online.

 If you are an accountant user and doing this for a client, you can follow the steps below:

1. From the left menu, select Taxes and click the Sales Tax.
2. Select the Returns tab and locate the sales tax filing that you'd like to un-file.
3. Under the Action column, open the drop-down menu to view options. Then, select Undo filing.
4. A window will appear asking Are you sure you want to go back? Review the information displayed and click Undo filing.
5. A notification will appear next to your open filing, highlighting the date that the return was reopened.

Otherwise, you’ll have to contact our support team for further assistance. Our agents also can help you undo the filing so you can make corrections as needed. 

If you have any other follow-up questions, let me know by commenting below. I'm always here to answer it for you. Have a great day!