Unfortunately, you can't cancel an extension that is in pending status. However, if it rejects, you will be able to make any needed changes.
To confirm that your Extension was accepted by the
IRS, click here: https://turbotax.intuit.com/tax-tools/efile-status-lookup/.
If there was a mistake on your extension, there is no need to worry. The
numbers used on your extension don't affect your actual return in any way.
