Don’t worry! If you suddenly remember a tax payment you made after you already filed your return, you can submit an amended return. If you’ve already filed, you can use Form 1040X to correct your return. On Form 1040X, you can report the payment and request a refund.
Go to this section in Credit Karma Tax: Start Amended Return
Credit Karma Tax can help you file Form 1040X. When you submit your 1040X, you’ll need to include the original tax return and tax forms you’re amending, a copy of the 1040-ES payment voucher that went along with your quarterly payment or any IRS payment confirmation showing proof of payment.