how much is the late fee for taxes

For US federal income taxes, the late “fee” is usually a percentage-based penalty, not a flat dollar amount, and it depends on whether you filed late, paid late, or both.

Core numbers to know

• The late filing penalty is usually 5% of the unpaid tax per month (or part of a month), up to a maximum of 25% of the unpaid tax.

• The late payment penalty is usually 0.5% of the unpaid tax per month (or part of a month), also up to 25%.

• If your return is more than 60 days late, there is a minimum late-filing penalty : the lesser of a fixed dollar amount (for 2026 returns, $525) or 100% of the tax you still owe.

How they stack together

• If you are both late filing and late paying in the same month, the IRS reduces the filing penalty to 4.5% and adds the 0.5% payment penalty, for a combined 5% per month, up to 25% of the unpaid tax.

• Once you hit the 25% maximum for a given penalty, that particular penalty stops increasing, but interest continues to accrue on the unpaid balance until you pay in full.

When there is no penalty

• If you are due a refund and do not owe tax, there is generally no late payment or late filing penalty (though you can lose the refund if you wait too many years to file).

• Filing an extension on time and paying your estimated tax due by the regular April deadline usually avoids late-filing penalties, though you can still incur late-payment penalties if you underpay.

Quick example

• If you owe $1,000 and file and pay one month late with no extension, a common outcome is about $50 in combined penalties for that month (around 5% of the unpaid tax), plus a small amount of interest.

Because state tax rules are different, checking your specific state’s revenue or tax department website is important if you are asking about state income tax late fees, property tax late fees, or local taxes.