Skip to main content
/

Pay by January 15 to cover Q4 — don't wait until April. Underpayment penalties accrue from the due date, not from filing.

Source: IRS Publication 505

Common Questions

The IRS charges a penalty equal to the federal short-term rate + 3% (currently ~8%). It's not huge, but it compounds daily. Pay as soon as you can — partial payments reduce the accruing penalty.

Only if you expect to owe $1,000+ after withholding. Your W-2 withholding may cover it — use the W-4 Optimizer to check whether you need to adjust withholding instead of making separate quarterly payments.

Yes, and it's often smart. Overpayments apply as a credit toward next year or are refunded. If your income varies, overpaying Q3 and Q4 is a common strategy to hit safe harbor.