Missed the October 15 Extension Deadline? What Happens and What to Do

Checked against IRS.gov in September 2026

What the extension did and didn’t do

IRS.gov explains that an extension “gives you until October 15 to file without penalties” and adds: “Make sure you pay any tax you owe by the April filing date” (IRS: Get an extension to file your tax return). So if you filed an extension in April and haven’t filed your return, two separate clocks may be running now:

• Late payment on any tax you didn’t pay by April. This one started in April.
• Late filing, which starts after October 15 because the extension covered you until then.

Some taxpayers in federally declared disaster areas have later deadlines. Check the IRS disaster relief page before assuming you’re late (IRS: Tax relief in disaster situations).

How the penalties add up after October 15

Failure to file

The IRS charges 5% of the tax due (less tax paid on time and credits) for each month or partial month the return is late, up to a maximum of 25% (IRS: Failure to file penalty; IRC §6651(a)(1)). If the return is more than 60 days late, a minimum penalty applies. The IRS adjusts that minimum amount each year and lists it on the same page.

Failure to pay

The late-payment penalty is 0.5% of the unpaid tax per month or partial month, up to 25% (IRC §6651(a)(2)). If you set up an approved payment plan, it drops to 0.25% a month while the plan is in place. If you don’t pay within 10 days of a notice of intent to levy, it rises to 1% a month (IRS: Failure to pay penalty).

When both apply in the same month

The two penalties don’t simply stack. The IRS reduces the failure-to-file penalty by the failure-to-pay penalty for that month, so instead of 5% plus 0.5%, it charges 4.5% plus 0.5% (IRS: Failure to pay penalty).

Interest

Interest runs on unpaid tax from the April due date, and on some penalties, until the balance is paid. The rate is the federal short-term rate plus 3%, set every quarter and compounded daily (IRS: Interest on underpayments and overpayments).

What to do this week

1. File the return. The failure-to-file penalty is ten times the failure-to-pay penalty, and filing stops it from growing.
2. Pay what you can with the return. Every dollar paid stops penalties and interest on that dollar.
3. Look at your options for the rest. Short-term extensions to pay, payment plans, and in some cases an offer in compromise or currently not collectible status. Our overview of what to do if you can’t pay compares them. IRS payment plan setup fees vary by method; see IRS: Payment plans; installment agreements.
4. Open your mail. A balance-due notice such as a CP14 usually follows once the return is processed.

Asking the IRS to remove the penalty

The IRS offers three main kinds of penalty relief: first-time abatement and other administrative waivers, reasonable cause, and statutory exceptions (IRS: Penalty relief).

• Automatic Exemption from Penalty (new). Starting summer 2026, if you file an eligible original return late and IRS records show timely compliance over the prior three years, the IRS says it won’t assess the failure-to-file or failure-to-pay penalty, and you don’t need to contact it (IRS: Penalty relief due to First Time Abate or other administrative waiver).
• First Time Abate. Where the automatic exemption doesn’t apply, you can ask for this by phone or in writing if you have a clean compliance history. You don’t need to name it or send documents; the IRS checks your account (IRS: Penalty relief due to First Time Abate or other administrative waiver).
• Reasonable cause. For serious events outside your control, such as illness, a disaster or being unable to get records. You explain what happened and show that you acted as soon as you could (IRS: Penalty relief).

Penalty relief does not remove interest on the tax itself. See our penalty abatement page for how a request is prepared.

If this is more than one year

If October 15 isn’t the only deadline you’ve missed, and earlier years are also unfiled, the order in which you file and the IRS’s current filing requirements matter. See unfiled tax returns.

Frequently asked questions

Related guides and services

• Year-end IRS checklistEvery year-end IRS situation, in calendar order.
• Failure to file vs. failure to payWorked examples of both penalties.
• Payment plansPay the IRS monthly instead of all at once.
• Penalty abatementHow a penalty relief request is prepared.

This page is general information, not tax or legal advice for your situation. IRS dates and rules come from IRS.gov as of the dates shown; check IRS.gov for current information or speak with a licensed tax professional.