Determine whether you need to make estimated tax payments
Estimate your expected income for the year
Estimate your total tax liability for the year
Subtract withholding and tax credits from your estimated tax liability
Divide the remaining amount into quarterly payments
Use IRS Form 1040-ES to calculate the payment amount
Pay online through IRS Direct Pay
Pay through the Electronic Federal Tax Payment System
Pay by debit or credit card if available
Mail a check or money order with the payment voucher
Make each payment by the IRS due date
Keep records of each payment made
Recalculate payments if your income changes during the year