Make a note of the amount of the third stimulus payment you received (the maximum $1,400 per taxpayer and dependent), or if you received no payment, and keep any IRS notice you get that identifies the payment. Do the same for any subsequent payments that may be enacted. Give this information to your tax preparer with your 2021 tax “stuff” next year.
These payments are NOT taxable income. But they will need to be “reconciled” when preparing your 2021 tax return. If you didn’t get the full amount to which you were entitled you can claim the shortage as a refundable credit on the 2021 return.