A tax extension payment is money you send to the IRS when you ask for more time to file your tax return, but you still owe taxes
When you file for a tax extension, you get until October 15 to submit your return instead of April 15. But an extension to file is not an extension to pay. The IRS expects you to pay what you owe by the original April 15 deadline, even if your return is not finished. If you cannot pay the full amount by April 15, you can send a partial payment now and pay the rest later—that partial payment is an extension payment.
The IRS charges interest and penalties on any tax you owe but do not pay by April 15, regardless of whether you filed your return. An extension payment reduces the amount those charges apply to. If you owe $5,000 and send $2,000 by April 15, interest and penalties accrue only on the remaining $3,000.
Key Takeaways
- An extension payment is a partial or full payment of taxes you owe, sent by the April 15 deadline even though your return is not yet filed.
- Sending any amount by April 15 stops interest and penalties from building on that portion of your tax bill.
- You can make an extension payment by check, electronic transfer, credit card, or through the IRS Direct Pay system without a fee.
- If you cannot pay by April 15, the IRS offers payment plans and installment agreements that let you pay over time with a setup fee.
- Interest accrues daily on unpaid taxes at a rate set quarterly, and failure-to-pay penalties add 0.5% per month to the unpaid balance.
How extension payments differ from regular tax payments
A regular tax payment is money you send when you file your return on time. An extension payment is money you send before you file, to reduce the interest and penalties that will accrue on the balance you still owe.
The mechanics are identical—you use the same payment methods and the IRS processes them the same way. The difference is timing and intent. With a regular payment, you have filed your return and know exactly what you owe. With an extension payment, you are guessing at your liability because your return is not complete. You are betting that the amount you send will cover at least part of what you will owe when you do file.
If your extension payment turns out to be more than you owe, the IRS will refund the overage or apply it to next year's taxes. If it is less than you owe, interest and penalties continue to build on the shortfall.
When you need to send an extension payment
You need to send an extension payment if all three of these are true: you cannot file your return by April 15, you expect to owe taxes (not receive a refund), and you cannot pay the full amount you think you will owe by April 15.
If you are expecting a refund, you do not need to send an extension payment. Filing late does not cost you anything if the IRS owes you money. If you owe taxes but can pay the full amount by April 15, you do not need an extension payment either—you can simply wait until you file to pay.
Extension payments are most common for self-employed people, business owners, and anyone whose tax situation is complicated enough that they need extra time to gather documents or calculate what they owe.
How to calculate and send an extension payment
To calculate an extension payment, estimate what you think you will owe when your return is complete. This is a guess, so be conservative—overestimate rather than underestimate. Subtract any taxes already withheld from your paychecks or paid through quarterly estimated tax payments. The remainder is what you should send by April 15.
You can send an extension payment by check, money order, electronic bank transfer, or credit card. The IRS Direct Pay system (available at irs.gov) lets you transfer money from your bank account for free and shows you immediately whether the payment was received. Credit card payments go through third-party processors and carry a convenience fee of 1.5% to 3.93% of the payment amount, depending on the processor.
Write your Social Security number or Employer Identification Number on a check. Include a note saying the payment is for an extension. Mail it to the address listed on the IRS website for your state. Do not mail it to the address on your tax form—that goes to a different location.
Interest and penalties on unpaid taxes after April 15
The IRS charges two separate costs on any tax you owe but do not pay by April 15: interest and penalties. Interest is calculated daily and compounds. The rate changes every quarter and is set by the IRS based on the federal short-term interest rate. As of early 2024, the rate is 8% per year, but this varies and you should check the IRS website for the current rate.
The failure-to-pay penalty is 0.5% of your unpaid tax per month, up to a maximum of 25%. This penalty accrues whether or not you filed your return on time. If you file late and owe taxes, you may also owe a failure-to-file penalty of 5% per month, up to 25%, but this penalty stops accruing once you file.
An extension payment stops both interest and penalties from accruing on the amount you send. If you send $2,000 of a $5,000 bill by April 15, interest and penalties apply only to the remaining $3,000.
Payment plans and installment agreements if you cannot pay in full
If you cannot send even a partial extension payment by April 15, the IRS offers short-term and long-term payment plans. A short-term plan lets you pay within 180 days with no setup fee. A long-term installment agreement spreads payments over months or years and requires a setup fee of $31 to $225, depending on how you set it up and your income level.
You can set up a payment plan online through the IRS website, by phone at 1-800-829-1040, or by mail. The IRS will tell you the monthly payment amount based on what you owe and how long you want to take to pay it. Interest and penalties continue to accrue on the unpaid balance, but a payment plan shows the IRS you are making a good-faith effort to pay, which can matter if you face enforcement action later.
If you set up a payment plan after April 15, you will owe interest and penalties on the full amount from April 15 onward. Setting up a plan does not erase or reduce the interest and penalties that have already accrued.
What happens if you miss an extension payment deadline
If you do not send an extension payment by April 15 and do not set up a payment plan, the IRS will begin sending notices. The first notice, called a CP14, arrives about 30 days after April 15 and shows what you owe plus interest and penalties accrued so far. You have 10 days to respond.
If you ignore the notices, the IRS can place a lien on your property, garnish your wages, or seize your bank account. These enforcement actions do not happen immediately—there is usually a gap of several months between the first notice and enforcement—but they do happen if you do not respond or set up a payment plan.
If you receive a notice and cannot pay, call the IRS immediately or set up a payment plan online. The sooner you respond, the more options you have.
Frequently Asked Questions
Do I need to file Form 4868 to send an extension payment?
Yes. Form 4868 is the Application for Automatic Extension of Time to File U.S. Individual Income Tax Return. You must file it by April 15 to get the extension to October 15. You can file it electronically through tax software or by mail. Filing Form 4868 does not automatically send a payment—you have to send the payment separately.
Can I make an extension payment after April 15?
Yes, but interest and penalties will have already started accruing on the unpaid balance as of April 15. Sending a payment after April 15 stops interest and penalties from building further, but does not erase what has already accrued. The sooner you pay, the less interest you will owe.
What if I send an extension payment but then file and owe less than I sent?
The IRS will refund the overage to you, usually within a few weeks of processing your return. You can also ask them to apply the overage to next year's tax bill instead of refunding it.
Can I use a credit card to make an extension payment?
Yes, but you will pay a convenience fee of 1.5% to 3.93% on top of the payment amount. The fee goes to the third-party processor, not the IRS. Bank transfer through IRS Direct Pay is free and usually faster.
Does an extension payment count toward my quarterly estimated taxes for next year?
No. An extension payment is for the current year's tax bill. Quarterly estimated taxes are separate payments for next year's expected tax liability. You need to track and pay both.