Will I owe a penalty if I file a tax extension?
Estimate whether a filing extension could trigger penalties or interest by entering your expected balance due and payment timing. The tool summarizes common IRS extension rules for 2025 and 2026, helping you plan how much to pay by the deadline to minimize late-payment penalties.
How this calculation works
- Starts with expected tax due and any payments already made.
- Estimates remaining balance and applies extension timing assumptions.
- Highlights potential penalty exposure based on unpaid amounts.
Common mistakes and caveats
- Penalty rates and rules can change; verify with IRS guidance.
- Interest continues to accrue on unpaid balances even with an extension.
FAQ
Does an extension give me extra time to pay?
No. An extension gives more time to file, but tax is still due by the original deadline.
How do I reduce extension penalties?
Pay as much as possible by the deadline; penalties are based on unpaid balances.
Last updated & sources
Last updated January 15, 2026.
TaxGuide Pro provides free state and federal tax calculators for individuals, freelancers, and small businesses.