QuickBooks will mark your tax return as Mark as filed after submitting it.
You'll need to contact the QuickBooks Chat Support Team to unfile a tax return. Just make sure you have this information ready so they can unfile it for you:
QuickBooks Online Company ID.
Which tax filing period you wish to unfile.
Here's how to get your company ID:
Go to the Gear icon and select Account and Settings.
Proceed to the Billing and subscription tab.
Look for the company ID in the upper-part of the screen.
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