The IRS charges penalties and interest if you file late, but the consequences depend on whether you owe money or are due a refund

If you miss the April 15 important date to file your federal tax return, the IRS will charge you a failure-to-file penalty — but only if you owe taxes. The penalty is 5% of the unpaid tax for each month or part of a month that your return is late, up to 25% total. You also owe interest on any unpaid tax, calculated daily from the original due date. The interest rate changes quarterly and is set by the IRS; for 2024, it is 8% per year.

If you are due a refund, there is no penalty for filing late — but you do lose money by waiting. The IRS will not send your refund until you file, and you cannot claim it after three years. If you file in year four, that refund is gone.

The IRS does not automatically know you missed the important date. They discover it when they match your W-2s and 1099s to your Social Security number and find no return on file. This can take months or years, depending on your income level and whether you have other red flags.

Key Takeaways

  • You owe a failure-to-file penalty of 5% per month (up to 25%) only if you owe taxes; there is no penalty if you are due a refund.
  • Interest accrues on unpaid tax from April 15 onward, regardless of when you file, and compounds daily.
  • If you are due a refund, you must file within three years or lose it permanently.
  • Filing even one day late triggers penalties, but the IRS may grant relief if you have a reasonable cause, such as a death in the family or a serious illness.
  • An extension gives you until October 15 to file, but does not extend the time to pay taxes owed — interest and penalties still accrue if you do not pay by April 15.

How penalties and interest stack up over time

The failure-to-file penalty and interest are separate charges that both grow the longer you wait. If you owe $5,000 in tax and file six months late, you owe a penalty of $1,500 (5% × 6 months × $5,000) plus interest calculated daily on the $5,000 from April 15. After one year, the penalty alone reaches $2,500 (5% × 12 months), and interest keeps compounding.

The IRS also charges a failure-to-pay penalty if you file on time but do not pay the tax you owe by April 15. This penalty is 0.5% per month, up to 25%, and it stacks on top of the failure-to-file penalty if you both file and pay late. Together, they can reach 50% of your unpaid tax before interest is added.

Interest is not capped. It accrues every day until you pay in full, and the IRS charges interest on the penalties themselves — a process called "compounding." This is why the total amount owed can grow much larger than the original tax bill.

What happens if you owe money and cannot pay

If you file late and owe tax but cannot pay the full amount, file anyway. The penalties are smaller if you file than if you do not file. A failure-to-file penalty is 5% per month; a failure-to-pay penalty is 0.5% per month. Filing stops the larger penalty from growing.

Once you file, you can set up a payment plan with the IRS. A short-term extension gives you 120 days to pay without a formal agreement. A long-term installment agreement lets you pay in monthly installments; the IRS charges a setup fee (usually $31 to $225, depending on how you set it up) and interest continues to accrue. You can request an installment agreement by phone, mail, or through the IRS website.

If you are in serious financial hardship, you may be able to request Currently Not Collectible status, which temporarily pauses collection action. Interest and penalties still accrue, but the IRS stops pursuing payment while you recover. This status lasts up to 120 days and can be renewed.

Filing an extension does not stop penalties if you owe tax

An extension (Form 4868) moves your filing important date from April 15 to October 15 — six extra months. Many people think an extension also delays the payment important date, but it does not. If you owe tax, it is still due on April 15, even if you file your return in October.

If you file an extension but do not pay by April 15, you owe both failure-to-pay interest and penalties on the unpaid amount. The failure-to-file penalty does not explore because you filed before October 15, but the failure-to-pay penalty (0.5% per month) starts accruing on April 16. An extension is useful if you need time to gather documents or calculate your tax, but it does not reduce what you owe or when you owe it.

You can request an extension by filing Form 4868 by April 15. The IRS usually grants it automatically if you file the form on time, even if you do not include payment.

How to request penalty relief

The IRS can remove or reduce penalties if you have reasonable cause — a legitimate reason beyond your control that prevented you from filing or paying on time. Common reasons include death or serious illness in your family, a natural disaster, a fire or theft that destroyed your records, or reliance on a tax professional who gave you incorrect information.

To request relief, file your return and include a written explanation of why you missed the important date. Mail it with your return or call the IRS at 1-800-829-1040 after you file. The IRS reviews your history: if you have filed and paid on time for the past three years, they are more likely to grant relief than if you have a pattern of late filings.

You can also request First-Time Penalty Abatement if you have never been penalized before and you file and pay within the grace period (usually a few weeks after the important date). This is an automatic waiver for first-time filers, though you still owe interest.

What happens if you never file

If you do not file for multiple years, the IRS will eventually send you a notice. The agency matches W-2s and 1099s to your Social Security number; when they find income reported to them but no return filed, they send a letter asking you to file. If you ignore the letter, the IRS can file a Substitute for Return (SFR) on your behalf using only the income they have on record.

An SFR is not the same as your actual return. It does not include deductions, credits, or dependents — only income. This means you often owe more tax than you actually should. You still owe penalties and interest, and the IRS can pursue collection through wage garnishment, bank levies, or a lien on your property.

If you have not filed in years, file now. The IRS has a statute of limitations: they can only assess tax for the past 10 years (with some exceptions for fraud). Filing stops the clock on penalties and interest and gives you a chance to claim any refunds you are due.

State tax important date and penalties

Most states follow the federal April 15 important date, but some have different dates. A few states do not have an income tax at all. If you owe state tax and file late, your state charges its own penalties and interest, which are separate from federal charges. State penalties vary: some states charge 5% per month like the federal government, while others charge a flat percentage or a fixed dollar amount.

If you file your federal return late, file your state return at the same time. Do not assume that filing federal covers state — they are separate filings and separate penalties.

Frequently Asked Questions

Can the IRS forgive penalties if I have a good reason?

Yes, if you have reasonable cause — such as a serious illness, death in the family, or a natural disaster — you can request penalty relief by mail or phone after you file. The IRS is more likely to grant relief if you have a clean filing history for the past three years. First-time filers may also may have access to for automatic penalty removal if they file within a grace period.

What if I filed an extension but still missed October 15?

You owe the same penalties as if you missed April 15. The failure-to-file penalty is 5% per month from April 15 onward, not from October 15. Filing an extension only moves your filing important date; it does not reset the penalty clock.

Do I owe penalties if I am due a refund?

No failure-to-file penalty applies, but you do lose money by waiting. The IRS will not send your refund until you file, and you cannot claim a refund after three years. If you file in year four, that money is gone.

How long does the IRS have to catch me if I do not file?

The IRS can assess tax for the past 10 years in most cases, though the timeline is longer if you underreported income by 25% or more. They discover unfiled returns by matching W-2s and 1099s to your Social Security number, which can take months or years depending on your income level.

Can I set up a payment plan if I file late and owe money?

Yes. Once you file, you can request a short-term extension (120 days) or a long-term installment agreement through the IRS website, by phone, or by mail. The IRS charges a setup fee and interest continues to accrue, but you avoid wage garnishment or bank levies while you pay.