Yes, the IRS charges penalties and interest if you file after the deadline

If you miss the tax filing deadline — normally April 15 — the IRS charges two separate penalties. The failure-to-file penalty is 5% of the unpaid tax for each month or part of a month your return is late, up to 25% total. The failure-to-pay penalty is 0.5% of unpaid tax per month, also capping at 25%. On top of both penalties, you owe interest on the unpaid amount, compounded daily. Interest rates change quarterly; the IRS publishes the current rate on its website.

The penalties apply only to taxes you actually owe. If you filed late but are owed a refund, you face no penalty — though you do lose the refund if you wait more than three years to file. The IRS can also add a penalty for not paying estimated taxes if you're self-employed, but that's a separate calculation.

Key Takeaways

  • Filing late costs 5% of unpaid tax per month (up to 25%) plus 0.5% per month for not paying, plus daily interest.
  • If you're owed a refund, there is no penalty for filing late, but you forfeit the refund after three years.
  • Requesting an extension before April 15 gives you until October 15 to file without penalty, though you still owe taxes by April 15.
  • The IRS may waive penalties if you have reasonable cause — a serious illness, natural disaster, or first-time mistake — but you must request it in writing.
  • Interest accrues daily and cannot be waived, even if penalties are forgiven.

How the failure-to-file and failure-to-pay penalties work together

Both penalties can apply at the same time. If you owe $5,000 in tax and file three months late without paying, you owe 15% in failure-to-file penalties ($750) plus 1.5% in failure-to-pay penalties ($75), plus interest on the $5,000. The failure-to-file penalty is larger and accrues faster, so filing even a few days late costs more than paying late if you've already filed.

If you file on time but don't pay, only the failure-to-pay penalty applies — 0.5% per month. This is why filing on time matters even if you can't pay in full. You can also set up a payment plan with the IRS to spread the cost over months, which stops the failure-to-pay penalty from growing once the plan is in place.

Filing an extension stops the failure-to-file penalty but not failure-to-pay

An extension gives you until October 15 to file without triggering the failure-to-file penalty. You request it using Form 4868, which you can file online through the IRS website or through tax software. The extension is automatic — the IRS approves it as long as you request it by April 15.

However, an extension does not extend your payment deadline. Taxes are still due April 15. If you don't pay by then, the failure-to-pay penalty and interest begin accruing even though you have until October to file. Many people file an extension, pay what they estimate they owe by April 15, and then file the actual return in the fall with any adjustments. This approach minimizes penalties.

Interest compounds daily and cannot be waived

The IRS charges interest on any unpaid tax from the due date forward, whether or not you file late. Interest is compounded daily — meaning interest accrues on the interest itself — and the rate changes every quarter. For 2024, the rate is 8% annually for most taxpayers, though it varies slightly for corporations and certain other situations.

Unlike penalties, interest cannot be forgiven. The IRS will waive penalties for reasonable cause, but interest is considered a debt owed to the government and is not subject to waiver. If you owe $5,000 and wait six months to pay, you will owe roughly $200 in interest alone, on top of penalties.

Requesting penalty relief if you have reasonable cause

The IRS can waive penalties if you show reasonable cause — meaning you had a good reason for filing or paying late that was beyond your control. Common reasons include serious illness or injury, death in the family, a natural disaster, or relying on incorrect advice from a tax professional. A first-time mistake or simple oversight may also may have access to, especially if you have a clean filing history.

To request relief, file Form 843 (Claim for Refund and Request for Abatement) with the IRS, or call the IRS at 1-800-829-1040 and ask to speak with a representative about penalty relief. You must provide documentation of your reason — a hospital record, death certificate, or written statement from your tax preparer, for example. The IRS reviews the request and decides whether to grant it. This process can take several months.

What happens if you never file or pay

If you owe tax and don't file or pay, penalties and interest continue to grow. After a certain point, the IRS may file a substitute return on your behalf using only income it knows about (W-2s, 1099s, etc.), which often results in a higher tax bill than you would have owed. The IRS can also place a lien on your property, garnish your wages, or seize your bank account to collect the debt.

If you owe back taxes from multiple years, the IRS typically pursues the oldest debt first. Filing late is always better than not filing at all, because filing gives you control over what income and deductions are reported.

Frequently Asked Questions

Does filing an extension prevent all penalties?

No. An extension prevents the failure-to-file penalty but not the failure-to-pay penalty. You still owe taxes by April 15, and if you don't pay, interest and the failure-to-pay penalty begin accruing. The extension only delays when you have to file the return itself.

What if I file late but I'm owed a refund?

You face no penalty. However, the IRS will not pay refunds older than three years. If you file more than three years late, you lose the refund entirely. Interest does not apply to refunds.

Can the IRS waive interest?

No. Interest is a debt owed to the government and cannot be forgiven under any circumstances. The IRS can waive penalties for reasonable cause, but interest will always be owed and will continue to compound daily until paid.

How much does interest cost if I wait several months to file and pay?

Interest depends on the amount owed and how long you wait. The rate is roughly 8% annually (as of 2024), compounded daily. On $5,000 owed for six months, you would owe approximately $200 in interest alone, plus penalties. The exact amount depends on the current quarterly rate.