Have a similar question about 20211040 ES Payment Vouchers. I received a one time special payment in 2020 from my employer (besides my regular salary). When the payment was made taxes were not withheld on half of the payment. My employer reported the income to IRS, half as regular income, the other half was reported on a Form 1099-INT. I filed my taxes and paid additional taxes on the funds reported on the Form 1099-INT. I E-Filed and paid my taxes due for 2020 in whole. Return was accepted by IRS. I printed up return. Four quarterly 20211040 ES Payment Vouchers were printed with my return automatically. I do not expect a similar tax situation in 2021. I will increase my withholding to avoid paying taxes in 2021.
