You may not be able to amend your return for the Recovery Rebate. If you already filed your return and it has been accepted, then you need to wait until your return has been fully processed (refund received or payment withdrawn), the IRS is making corrections regarding the entry of the Recovery Rebate Credit. If the IRS corrects your return, they will send you a letter regarding what they changed.
The following is information from the IRS regarding who can amend their return for the Recovery Rebate Credit:
The following is from the IRS about amending a return for the Stimulus payment:
1) If you didn't claim the credit on your original tax return you will need to file a Form 1040-X, Amended U.S. Individual Income Tax Return, to claim it. The IRS will not calculate the 2021 Recovery Rebate Credit for you if you did not enter any amount on your original tax return, or you entered $0.
(2) DO NOT file an amended tax return if you entered an incorrect amount for the 2021 Recovery Rebate Credit on your tax return. If you entered an amount other than $0 on line 30 but made a mistake in calculating the amount, the IRS will calculate the correct amount of the 2021 Recovery Rebate Credit, make the correction to your tax return, and continue processing your return. If a correction is needed, there may be a delay in processing your return and the IRS will send you a notice explaining any change made.
https://www.irs.gov/newsroom/2021-recovery-rebate-credit-topic-h-correcting-issues-after-the-2021-ta...
