The Short Answer
Missing the April 15 deadline without filing an extension triggers two separate IRS penalties — and they compound monthly. But the damage depends entirely on whether you owe money or are owed a refund.
If You're Owed a Refund
No penalty. The IRS owes you money, not the other way around. You can file months or even years late. The only catch: you have a 3-year window from the original due date to claim your refund. File after April 15, 2029, and the IRS keeps your 2025 refund permanently.
If You Owe Taxes: The Two Penalties
Penalty 1: Failure-to-File (5% per month)
This is the big one. The IRS charges 5% of your unpaid tax balance for every month (or partial month) your return is late, up to a 25% maximum.
| Months Late | Penalty Accumulated |
|---|---|
| 1 month | 5% |
| 2 months | 10% |
| 3 months | 15% |
| 4 months | 20% |
| 5 months | 25% (maximum) |
On a $5,000 tax bill, that's up to $1,250 in failure-to-file penalties alone.
Penalty 2: Failure-to-Pay (0.5% per month)
A separate, smaller penalty of 0.5% per month on unpaid taxes, also capping at 25%. This continues even after you file — until the balance is paid in full.
Key rule: Always file your return even if you can't pay. The failure-to-file penalty is 10× the failure-to-pay penalty. Filing stops the larger penalty clock immediately.
Interest on Top of Penalties
The IRS also charges interest on unpaid taxes and penalties, compounded daily. The current rate is the federal short-term rate + 3% (approximately 7–8% annually). Interest is not capped and continues until the full balance is paid.
What to Do Right Now
Step 1: File your return immediately (even without full payment)
Filing stops the 5%/month failure-to-file penalty. You can owe the money and set up a payment plan separately.
Step 2: Pay as much as you can today
Every dollar paid reduces the base on which penalties and interest are calculated.
Step 3: Set up an IRS payment plan
If you owe $50,000 or less, you can set up an online installment agreement at irs.gov in minutes — no phone call required. The failure-to-pay penalty drops to 0.25%/month while you're in an active payment plan.
Step 4: Consider a penalty abatement request
If this is your first time missing a deadline (and you have a clean compliance history), you may qualify for First-Time Penalty Abatement. Call the IRS or submit Form 843. This can eliminate the failure-to-file and failure-to-pay penalties — but not interest.
Penalty Summary
| Situation | Penalty |
|---|---|
| Filed on time, can't pay | 0.5%/month on unpaid balance |
| Filed late, owed money | 5%/month (up to 25%) + 0.5%/month |
| Filed late, no tax owed | No penalty |
| Filed late, owed a refund | No penalty (3-year refund window) |
| No return filed at all | 5%/month until filed or IRS files substitute |
The One Rule to Remember
Always file, even if you can't pay.
The failure-to-file penalty (5%/month) is the most damaging. Filing a return — even a partial or estimated one — stops it immediately. You can negotiate the payment separately.
Use our Tax Refund Estimator to see if you owe or are owed money before deciding how urgently to act.