You must make estimated tax payments for the current tax year if both of the following apply:

There are special rules for:

If you are required to make estimated tax payments, self-employment tax is paid by making quarterly estimated tax payments which include both income tax and social security tax.

For estimated tax purposes, the year is divided into four payment periods. Each period has a specific payment due date. If you do not pay enough tax by the due date of each of the payment periods, you may be charged a penalty even if you are due a refund when you file your income tax return.

If a payment is mailed, the date of the U.S. postmark is considered the date of payment. The payment periods and due dates for estimated tax payments are shown next.

For the period: Due date:
Jan. 11– March 31
April 15
April 1 – May 31 June 15
June 1 – August 31 September 15
Sept. 1 – Dec. 31 January 15
next year2

Take credit for all your estimated tax payments in the "Payments" section of Form 1040 (PDF), U.S. Individual Income Tax Return, line 62 or Form 1040A (PDF), U.S. Individual Income Tax Return line 39.