IRS Late Filing and Late Payment Penalties: How They Are Calculated and How to Lower Them
How IRS failure-to-file and failure-to-pay penalties and interest work, with a worked example, the minimum and ways to reduce the bill.
IRS Late Filing and Late Payment Penalties
Missing the tax deadline feels like a disaster, but the cost depends on two separate choices: whether you filed and whether you paid. The penalties are different, they grow at different speeds and the cheapest move is often to file right away, even if you cannot pay. The IRS Late Filing and Late Payment Penalty and Interest Calculator shows how the pieces add up.
Three charges, not one
- Failure-to-file penalty. 5 percent of the unpaid tax for every month or part of a month the return is late, up to 25 percent.
- Failure-to-pay penalty. 0.5 percent of the unpaid tax for every month or part of a month after the due date, up to 25 percent.
- Interest. Charged on the unpaid tax from the due date until you pay, at the federal short-term rate plus 3 percentage points, adjusted every quarter and compounded daily.
How the two penalties interact
In every month when both apply, the failure-to-file penalty is reduced by the failure-to-pay penalty. In practice the combined rate is 5 percent a month: 4.5 percent for failing to file plus 0.5 percent for failing to pay. After five months the filing penalty stops at 22.5 percent, and the payment penalty continues at 0.5 percent a month until it reaches 25 percent. This is why filing on time and paying late is far cheaper than not filing at all.
The minimum penalty
If your return is more than 60 days late, the failure-to-file penalty is at least the smaller of $525 (for returns due in 2026) or the full tax you owe. For a small balance, this minimum can be larger than the percentage calculation. The figure is editable in the table, since it is adjusted for inflation each year.
An extension is not an extension to pay
Filing Form 4868 gives you until October to file, and removes the failure-to-file penalty, but tax not paid by the original due date still carries the payment penalty and interest. If you expect to owe, pay an estimate with the extension.
A worked example
You owe $6,000 after credits and withholding, the due date was April 15, 2026, and you file and pay on October 15. The return is seven months late, counting part months. The failure-to-file penalty is 4.5 percent times seven months, but the cap of 22.5 percent applies: $1,350. The failure-to-pay penalty is 0.5 percent times seven months, $210. Interest for 183 days at 7 percent (6 percent in the second quarter), compounded daily, is about $200. The extra cost is about $1,760, and the total due is about $7,760. Had you filed on time and only paid in October, the filing penalty would disappear and the extra cost would be about $410.
How to lower the bill
- File now. Every month of delay adds to the filing penalty.
- Pay what you can. Interest and the payment penalty run on the unpaid balance.
- Ask for first-time abatement. If you had no penalties in the last three years and filed all required returns, the IRS may remove them.
- Show reasonable cause. Serious illness, a disaster or an inability to get records can be reasons.
- Set up an installment agreement. It lowers the failure-to-pay rate to 0.25 percent a month while the agreement is in force.
What the calculator leaves out
Interest on the penalties themselves, state penalties, the accuracy-related penalties and relief are not included. The IRS notice shows the exact figures. This tool is an estimate and not tax advice.
