Taxes
Missed a Quarterly Estimated Tax Payment? Here's How to Fix It
The short answer
Pay it as soon as you can — don't wait for the next quarterly due date. The penalty for a missed estimated payment isn't a flat fine; it works like interest (currently 7% per year, prorated daily) that keeps accruing until you pay. Then recalculate the remaining quarters so the rest of the year is covered, or use extra paycheck withholding to catch up — withholding is treated as if it were paid evenly all year.
The quarterly estimated-tax calendar is one of the least intuitive things the IRS asks of self-employed people and S-corp owners — the "quarters" aren't even the same length. Missing one happens to careful people all the time. Here's what it actually costs and how to close the gap cleanly.
Step 1 — Pay now, not at the next due date
The penalty accrues daily from the missed due date until the day the money arrives. Waiting for the next quarterly date just buys weeks of unnecessary accrual. Pay online at irs.gov/payments (IRS Direct Pay, from a bank account, free) and choose the correct tax year and "estimated tax" as the reason.
Step 2 — Understand what the penalty is (and isn't)
There's no flat fine and nobody is coming after one late quarter. The IRS charges the underpayment rate — 7% per year right now, recalculated quarterly — on the shortfall, for the days it was short. It's interest wearing a penalty costume. That's genuinely good news: it means the fix is simply speed.
Step 3 — Aim the rest of the year at a safe harbor
You owe no underpayment penalty at all if, by year end, your withholding and estimates reach the lesser of 90% of this year's tax or 100% of last year's (110% if your prior-year AGI topped $150,000). Recalculate the remaining quarters against that target so one missed payment doesn't quietly become four short ones.
Step 4 — Know the withholding trick (S-corp owners especially)
Tax withheld from a paycheck is treated as if it were paid evenly through the whole year — regardless of when it actually came out. Estimated payments don't get that treatment; they count only when paid. So if you run your own payroll, cranking up withholding on your remaining paychecks can retroactively "cure" an earlier missed quarter in a way a late estimated payment can't. It's the single most useful lever S-corp owners don't know they have.
Step 5 — Set up next year so this doesn't recur
The recurring version of this problem is a planning problem: nobody told the quarterly payments about the K-1 income, the strong year, or the new contract. That's exactly what our tax estimation work exists for — we project your full-year liability from your actual year-to-date numbers (K-1s, S-corp salary, business income, W-2 withholding), compare it to your safe harbor, and hand you the quarterly amounts with a safety buffer you choose.
2026 dates: April 15 · June 15 · September 15 · January 15, 2027. Put all four in your calendar now — the June one arrives faster than anyone expects.
Common questions
How much is the penalty for missing a quarterly payment, really?
It's computed like interest, not a ticket: the underpayment rate (7% per year as of the third quarter of 2026, reset quarterly by the IRS) applied to the shortfall for however many days it stays unpaid. Missing a $3,000 payment by one month costs roughly $17 — the danger isn't one late quarter, it's letting the shortfall snowball all year.
What are the estimated tax due dates for 2026?
April 15, June 15, and September 15, 2026, then January 15, 2027 for the final quarter. Note the uneven spacing — the second “quarter” is only two months long, which is exactly how organized people still get surprised.
What's the safe harbor rule?
You avoid the underpayment penalty entirely if your payments and withholding for the year reach at least 90% of this year's tax, or 100% of last year's tax (110% if your prior-year adjusted gross income was over $150,000). For most people the prior-year number is the reliable target because it's already known.
My income is uneven — big months and dry spells. Do I have to pay evenly?
No. Form 2210's annualized income method lets you match payments to when the income actually arrived, so a slow first half doesn't generate a penalty just because your fourth quarter boomed. It takes more math, but it's built for exactly this situation.