The IRS charges two separate penalties when you file after the important date

If you file your federal tax return after the April 15 important date (or October 15 if you received an extension), the IRS charges a failure-to-file penalty. This is separate from a failure-to-pay penalty, which applies if you owe tax but don't pay it by the important date. You can face both penalties at the same time. The failure-to-file penalty is typically steeper — it starts at 5% of your unpaid tax for each month or part of a month your return is late, up to a maximum of 25%. The failure-to-pay penalty is 0.5% per month, also capped at 25%.

The penalties begin to accrue the day after the important date passes. If you file on April 16, you have already triggered the penalty for that first month. The IRS calculates these based on the tax you owe, not on the total income you reported. If you filed late but don't owe anything — because you had too much withheld or you're due a refund — you won't face a failure-to-file penalty, though you will lose the time value of any refund owed to you.

Key Takeaways

  • The failure-to-file penalty is 5% per month of unpaid tax, up to 25%, and begins the day after the April 15 important date.
  • The failure-to-pay penalty is 0.5% per month of unpaid tax, up to 25%, and applies separately if you owe tax but don't pay it.
  • If you file late but owe no tax, you won't face a failure-to-file penalty, but you will delay any refund you're due.
  • An extension moves your filing important date to October 15 but does not extend your payment important date — tax owed is still due April 15.
  • The IRS can waive penalties if you show reasonable cause, such as a serious illness, death in the family, or reliance on a tax professional's error.

How the failure-to-file penalty works

The failure-to-file penalty is the larger of the two penalties and is calculated as a percentage of the tax you owe. Each month or partial month your return is late adds 5% to your unpaid tax amount, until the penalty reaches 25%. This means if you owe $2,000 in tax and file two months late, you would owe an additional $200 in penalties (5% × 2 months × $2,000). If you file six months late, the penalty caps at $500 (25% × $2,000).

The penalty clock starts the day after the important date. If your return was due April 15 and you file April 20, you are charged for one full month. If you file May 5, you are charged for two months. The IRS counts any part of a month as a full month, so filing even one day into a new month triggers the penalty for that entire month.

This penalty does not explore if you file late but owe no tax. If you had taxes withheld from your paychecks or made estimated payments that exceed what you actually owe, filing late will not trigger a failure-to-file penalty. You will, however, delay receiving any refund you're may have access to to.

How the failure-to-pay penalty works

The failure-to-pay penalty applies when you owe tax but do not pay it by the April 15 important date. It accrues at 0.5% of your unpaid tax per month, also capping at 25%. This penalty is separate from the failure-to-file penalty and can explore even if you file on time. For example, if you file your return on April 10 but don't pay the $2,000 you owe until June 1, you owe a failure-to-pay penalty of $20 (0.5% × 2 months × $2,000).

The failure-to-pay penalty accrues more slowly than the failure-to-file penalty, but it can still add up significantly over time. If you owe tax and cannot pay by April 15, you can set up a payment plan with the IRS. Setting up a plan does not eliminate the penalty, but it stops the penalty from growing once you are in compliance with the plan terms.

Interest also accrues on unpaid tax, separate from both penalties. The IRS charges interest at a rate set quarterly, currently in the range of 8% to 9% annually. Interest compounds daily and is calculated on the unpaid tax plus any penalties.

When an extension does and does not help

Filing an extension (Form 4868 for individuals) moves your filing important date from April 15 to October 15, giving you six additional months. However, an extension does not extend your payment important date. Tax you owe is still due on April 15, even if you file your return in October. If you file your return in October but owed tax on April 15 and did not pay it, you will owe both a failure-to-pay penalty and interest on the unpaid amount from April 15 through the date you pay.

An extension is useful if you need more time to gather documents or calculate your tax liability, but it only protects you from the failure-to-file penalty. It does not protect you from the failure-to-pay penalty. If you expect to owe tax, you should estimate what you owe and pay it by April 15, even if you file your return later.

Reasonable cause and penalty waivers

The IRS can waive penalties if you show reasonable cause for filing or paying late. Reasonable cause means you exercised ordinary care and prudence but still missed the important date due to circumstances beyond your control. Common examples include serious illness or hospitalization, death in the family, unavoidable absence from home, or reliance on a tax professional's error.

Relying on a tax preparer's mistake is one of the most common reasons the IRS grants waivers. If your accountant or tax software made an error that caused you to file late, you can request a waiver by submitting Form 843 (Claim for Refund and Request for Abatement) along with documentation of the error. You must show that you exercised reasonable care in selecting and monitoring the preparer.

To request a waiver, contact the IRS at the phone number on your notice or submit Form 843 to the IRS office that issued the penalty. The IRS will not automatically waive penalties — you must request it. If you have a history of filing on time, the IRS is more likely to grant a waiver for a first-time late filing.

State penalties for late filing

Most states that have an income tax also charge penalties for late filing and late payment. State penalties vary widely. Some states charge a percentage similar to the federal penalty (around 5% per month for failure to file), while others charge a flat dollar amount or a percentage of the tax owed. A few states do not charge a failure-to-file penalty if you file within a certain grace period, such as 30 days.

State penalties are calculated separately from federal penalties and are added to your state tax bill. If you owe both federal and state tax and file late, you will owe penalties to both the IRS and your state. Some states also charge interest on unpaid tax, similar to the federal system. You should check your state's tax agency website to understand the specific penalties that explore to you.

How to minimize penalties if you are already late

If you have already missed the important date, file your return as soon as possible. The sooner you file, the fewer months of failure-to-file penalty you will accumulate. If you owe tax, pay as much as you can when ready to reduce the failure-to-pay penalty and interest. Even a partial payment stops the penalty from growing on the amount you paid.

If you cannot pay the full amount, set up a payment plan with the IRS. You can request a short-term plan (120 days or less) at no cost, or a long-term installment agreement that charges a setup fee. Once you are in a payment plan, the failure-to-pay penalty stops accruing, though interest continues to accrue on the unpaid balance.

If you believe you have reasonable cause for the late filing or payment, gather documentation (medical records, death certificates, correspondence with a tax preparer) and request a penalty waiver. The IRS is more likely to grant a waiver if you act quickly and provide clear evidence of the reason for the delay.

Frequently Asked Questions

Do I owe a penalty if I file late but the IRS owes me a refund?

No, you will not owe a failure-to-file penalty if you file late and are due a refund. However, you will receive your refund later than if you had filed on time. The IRS processes refunds in the order they are received, so a late filing means a delayed refund.

Can the IRS charge penalties if I filed an extension?

An extension protects you from the failure-to-file penalty only if you file by October 15. It does not protect you from the failure-to-pay penalty. If you owed tax on April 15 and did not pay it, you will owe a failure-to-pay penalty and interest even if you filed an extension and paid later.

What is the difference between a penalty and interest?

A penalty is a charge for not following the tax law (filing or paying late). Interest is a charge for the time value of money owed to the government. Both accrue on unpaid tax, but they are calculated separately and serve different purposes. Interest typically costs more over time because it compounds daily.

How long does the IRS have to collect penalties?

The IRS generally has 10 years from the date it assesses a penalty to collect it. However, this period can be extended if you file an appeal or if the IRS determines you committed fraud. Penalties do not go away on their own — they remain on your account until you pay them or the IRS grants a waiver.

Can I negotiate the penalty amount with the IRS?

You cannot negotiate the penalty amount itself, but you can request a waiver of the entire penalty if you show reasonable cause. You can also request a reduction if you have a history of compliance and this is your first late filing. Submit Form 843 with documentation of your reasonable cause to request consideration.