April 15, 2026 was Tax Day. If you neither filed a return nor requested an extension, the IRS is already charging you money. Here is what it costs and how to minimize it.
The two penalties — they stack
1. Failure-to-file: 5% of unpaid tax per month, max 25%. Kicks in April 16. 2. Failure-to-pay: 0.5% of unpaid tax per month, max 25%. 3. Interest: ~8% annualized on unpaid balance, compounded daily.
If you filed an extension (Form 4868) by April 15 but didn't pay, you avoid penalty #1 — only pay penalty #2 + interest. Big difference.
What to do today
1. File now, even if you cannot pay. Filing stops penalty #1 immediately. Penalty #2 continues but at 10× smaller rate. 2. Set up an IRS payment plan. Short-term (under 180 days) is free. Long-term installment agreement costs $31-$225 setup, reduces the failure-to-pay penalty to 0.25%/month. 3. First-Time Abatement. If you have a clean compliance record for the past 3 years, call the IRS and request first-time penalty abatement. It's a one-call waiver most people don't know about.
Getting a refund? No penalty — but file anyway
If the IRS owes you money, there is no penalty for filing late. But: - Refund forfeits after 3 years (2023 refund vanishes April 15, 2027) - No Earned Income Tax Credit or Child Tax Credit without filing - Filing protects your Social Security earnings record
Run your numbers
Use our US Income Tax Calculator to estimate liability, and the Take-Home Pay Calculator to understand your ongoing withholding.