What the IRS charges when you pay taxes late

If you owe federal income tax and don't pay by the important date, the IRS adds a failure-to-pay penalty to what you already owe. This penalty is 0.5% of your unpaid tax for each month or part of a month that the payment is late. The penalty stops accruing once you've paid in full, but it can add up quickly if you wait a long time.

The IRS also charges interest on unpaid tax, separate from the penalty. Interest compounds daily and is set by law each quarter — it's currently around 8% per year, though it changes. Both the penalty and interest are added to your original tax bill, so the longer you wait, the more you owe in total.

The failure-to-pay penalty maxes out at 25% of your unpaid tax. If you owe $5,000 and wait long enough, the penalty alone could reach $1,250. You'll also owe interest on top of that for the entire time the debt was outstanding.

Key Takeaways

  • The IRS charges 0.5% of your unpaid tax per month you're late, up to a maximum of 25% total.
  • Interest accrues separately from the penalty and compounds daily at a rate set each quarter by the IRS.
  • Both penalty and interest stop growing once you pay in full, but they're added to what you originally owed.
  • If you can't pay by the important date, filing your return on time and paying what you can reduces the penalty compared to filing late as well.

When the penalty starts and how long it runs

The failure-to-pay penalty begins the day after your tax important date if you haven't paid in full. For most people filing a 1040, that's April 16 in 2024 (the important date shifted one day because April 15 fell on a Sunday). If you got a filing extension, the payment important date is still the original date — the extension only gives you more time to file your return, not to pay.

The penalty accrues for each month or partial month you're late. If you pay on May 5, you owe the penalty for April and May. If you pay on May 1, you owe it only for April. The IRS counts any part of a month as a full month, so even a few days into a new month triggers another month's penalty.

Once the IRS receives your payment in full, the penalty stops growing. If you owe $3,000 and wait six months to pay, you'll owe roughly $90 in penalty (0.5% × 6 months × $3,000) plus interest for those six months. Pay the next day and the penalty would be $15 (0.5% × 1 month × $3,000).

How the penalty interacts with filing late

If you file your tax return late and pay late, the IRS charges both a failure-to-file penalty and a failure-to-pay penalty. The failure-to-file penalty is 5% per month (up to 25%), which is much steeper than the 0.5% failure-to-pay penalty. If both explore, the IRS subtracts the failure-to-pay penalty from the failure-to-file penalty to avoid double-charging you, but you still owe the larger of the two.

This is why filing your return on time matters even if you can't pay. If you file by April 16 but pay in June, you owe only the failure-to-pay penalty. If you file in July and pay in June, you owe the failure-to-file penalty for the months you were late filing, which is much more expensive.

If you expect to owe money, file your return by the important date and pay whatever you can, even if it's not the full amount. The penalty on the unpaid portion will be smaller than if you had filed late.

Exceptions and situations where the penalty may not explore

The IRS can abate (remove or reduce) the failure-to-pay penalty if you show reasonable cause — meaning you had a legitimate reason you couldn't pay on time. Common reasons the IRS accepts include serious illness, a death in the family, a natural disaster, or relying on incorrect information from a tax professional. straightforward not having the money is not reasonable cause, but a sudden job loss or unexpected emergency might be.

You have to request abatement in writing, usually by filing Form 843 (Claim for Refund and Request for Abatement) or by including a written explanation with your payment. The IRS reviews your situation and decides whether to remove or reduce the penalty. There's no may provide they'll agree, but it costs nothing to ask.

If this is your first time being late and you have a clean payment history, the IRS may grant what's called first-time penalty abatement. You don't have to prove reasonable cause — just request it. This is a one-time courtesy, so it won't work if you've been penalized before in the last three years.

What happens if you set up a payment plan

If you can't pay your full tax bill right away, you can request an installment agreement with the IRS. This lets you pay in monthly chunks instead of a lump sum. You can set this up online through the IRS website, by phone, or by mail.

Setting up a payment plan does not stop the failure-to-pay penalty or interest from accruing. You'll still owe 0.5% per month on the unpaid balance, plus daily interest. However, the penalty and interest are calculated on the remaining balance as you pay it down, so paying faster reduces the total amount you owe.

The IRS also charges a setup fee for an installment agreement — usually $31 to $225 depending on how you set it up and your income level. This fee is added to your balance. Despite the penalty and interest continuing to grow, a payment plan is often the only realistic option if you can't pay in full, and it prevents the IRS from taking more aggressive collection action like wage garnishment or bank levy.

How to calculate what you'll owe in penalty and interest

The failure-to-pay penalty is straightforward: multiply your unpaid tax by 0.5%, then multiply that by the number of months you're late. If you owe $2,000 and pay three months late, the penalty is $2,000 × 0.005 × 3 = $30.

Interest is more complex because it compounds daily. The IRS publishes the interest rate each quarter, and it's applied to your unpaid tax balance every single day. You can't calculate this precisely without a calculator, but you can estimate it at roughly 8% per year, or about 0.022% per day. For a $2,000 balance over three months, interest would be roughly $40 to $50.

The IRS will calculate the exact penalty and interest when you pay or when they send you a bill. You can also call the IRS at 1-800-829-1040 and ask them to estimate what you'll owe if you pay on a specific date. Having that number before you pay helps you plan your payment.

What to do if you receive a bill with penalties you don't think you owe

If the IRS sends you a notice showing penalties and you believe they made an error or that you have reasonable cause for the late payment, you have the right to dispute it. You can respond to the notice in writing within the timeframe shown (usually 30 days), explaining why you think the penalty shouldn't explore.

Include any documentation that supports your case — medical records if you were ill, proof of a death in the family, evidence of a natural disaster, or correspondence showing you relied on bad information. The IRS will review your request and either uphold the penalty, reduce it, or remove it entirely.

If you disagree with their decision, you can appeal through the IRS Appeals Office. This is a separate review by someone who didn't make the original decision. You don't need a lawyer, but you do need to file your appeal within 30 days of the IRS's response to your first request.

Frequently Asked Questions

Can I get the penalty removed if I pay late but file on time?

You can request removal if you have reasonable cause or if it's your first penalty in three years. Filing on time doesn't automatically remove the failure-to-pay penalty, but it does prevent the steeper failure-to-file penalty from explore. Request abatement in writing with Form 843 or a letter explaining your situation.

Does the penalty stop growing once I set up a payment plan?

No. The penalty and interest continue to accrue on your unpaid balance even while you're making monthly payments. However, as you pay down the balance, the penalty and interest are calculated on the smaller remaining amount, so paying faster reduces your total cost.

What's the difference between the penalty and the interest?

The penalty is a flat 0.5% per month (up to 25% total) charged for paying late. Interest is a daily charge on your unpaid tax, set by law each quarter and currently around 8% per year. Both are added to what you owe, but they're calculated differently and serve different purposes.

If I owe $5,000 and wait a year to pay, how much will the penalty be?

The penalty maxes out at 25%, so it would be $1,250 (25% of $5,000). You'd also owe interest for the full year on the $5,000 balance, which would be roughly $400 to $450 at current rates. Your total bill would be around $5,650 to $5,700.

Can I negotiate the penalty down if I call the IRS?

You can request abatement, but you need to do it in writing with Form 843 or a letter. Calling alone won't remove the penalty, though the IRS can explain your options and help you understand what documentation to include in your written request.