Will I owe an underwithholding penalty for 2025?

Check underpayment penalty risk for 2025 or 2026 by entering prior‑year tax, prior‑year AGI, expected current tax, and payments to date. The tool tests IRS safe‑harbor thresholds (90% current or 100%/110% prior) and estimates any shortfall.

No login required.

How this calculation works

  • Calculates required payments based on safe‑harbor thresholds.
  • Compares required payments to amounts already paid or expected.
  • Summarizes the remaining gap and risk level.

Common mistakes and caveats

  • Annualized income methods and special rules are not modeled.
  • Timing of payments affects penalty calculations.
  • State penalties are not included.

FAQ

Does meeting safe harbor eliminate penalties?

Meeting safe harbor usually avoids underpayment penalties, but you may still owe tax at filing.

Last updated & sources

Last updated January 27, 2026.

TaxGuide Pro provides free state and federal tax calculators for individuals, freelancers, and small businesses.