I didn't pay enough taxes throughout the year — will the IRS charge me a penalty for 2025?

Yes, the IRS can charge an underpayment penalty if you didn't pay enough tax during the year through withholding or estimated quarterly payments. For 2025, the penalty rate is 8% annualized (based on the federal short-term rate + 3 percentage points). But here's the good news: there are safe harbors that completely eliminate the penalty.

### When Do You Owe a Penalty?

You generally owe an underpayment penalty if:

• Your total tax liability is $1,000 or more after subtracting withholding and refundable credits, AND
• You paid less than the safe harbor threshold (see below)

If your total tax owed is under $1,000, no penalty applies.

### Safe Harbor Rules — How to Avoid the Penalty Entirely

You avoid the underpayment penalty if you paid at least one of the following amounts during the year:

Option 1 is usually easier to use because you know your prior year tax exactly. If your 2024 tax bill was $8,000 and you had at least $8,000 withheld or paid in estimated payments during 2025, you owe no underpayment penalty — regardless of how large your 2025 bill turns out to be.

### How the Penalty Is Calculated

The underpayment penalty is calculated quarter by quarter — it's not just one lump sum. Each quarter you underpaid, the IRS charges interest on the shortfall for that period. This means even if you paid up before December 31, you might still owe a penalty for earlier quarters. The IRS calculates this automatically on Form 2210.

### What to Do Now

If you owe a large balance when you file, check whether you qualify for a safe harbor before assuming a penalty applies. If you're regularly underpaying, adjust your W-4 withholding at work or set up quarterly estimated payments (due April 15, June 16, September 15, and January 15) to avoid the issue next year.