Quarterly estimates, without the guesswork

If tax isn’t coming out of a paycheck, the IRS wants it in four installments — and the rules for “enough” are called safe harbor. Put in two numbers and you get your four payment amounts, the exact due dates, and exactly how to pay. So there are no surprises in April.

2026 tax year · federal + Indiana · due dates verified against the 2026 calendar.

Your numbers

2025 total tax — from last year’s return

Form 1040, “total tax” line. This anchors the safe harbor.

My 2025 income (AGI) was over $150,000

Over that line, the prior-year safe harbor is 110% instead of 100%.

Expected 2026 total federal tax (optional)

If you can estimate it, we use whichever safe harbor is cheaper. Leave blank and we plan off last year alone — which is the certain route.

Federal withholding you’ll have in 2026

From your (or your spouse’s) W-2 job, pension, etc. Withholding counts toward the harbor first.

2026 estimates you’ve already paid

Total sent so far this year, if any.

Indiana

Expected 2026 Indiana tax

State + county. A quick proxy: about 3% of income for the state, plus your county’s rate.

Indiana withholding you’ll have in 2026

2026 Indiana estimates already paid

Your schedule lands here.

Last year’s total tax is on your 2025 return — grab it and press Build my payment schedule.

Your 2026 safe-harbor plan

Federal — four payments, four dates

Indiana — same rhythm, same dates

How to pay — complete enough to do it right now

Federal, the easy way: IRS Direct Pay at irs.gov/payments — choose “Estimated Tax”, tax year 2026, and pay by bank e-check (free; skips the card fee). It takes about five minutes and you get a confirmation number — keep it.

Federal, by mail: check payable to “United States Treasury”, with your SSN and “2026 Form 1040-ES” on the memo line, sent with the 1040-ES voucher for that quarter to the address printed on the voucher.

Indiana, the easy way: INTIME at intime.dor.in.gov — make an individual estimated payment for 2026. No login required for a one-time payment.

Indiana, by mail: check payable to the Indiana Department of Revenue with Form ES-40, to the address printed on the form.

One boundary, stated plainly: every payment comes from you. We calculate the amounts and give you exact instructions — payee, amount, date, where and how — but Delta never makes, schedules, or submits a tax payment on your behalf. That line protects us both.

Estimate only — a Delta review is required before acting. Safe harbor protects you from penalties; it doesn’t guarantee the April balance is zero. If income lands higher than planned, you may still owe the difference at filing — the harbor just means no penalty on the way there. If your year changes mid-stream, the schedule should too.

What this schedule assumes — out in the open

The safe-harbor rule: no federal underpayment penalty if your 2026 withholding + estimates reach the smaller of 90% of your 2026 tax or 100% of your 2025 tax (110% if 2025 AGI was over $150,000).
Even quarters. Payments are spread equally. If your income arrives unevenly — seasonal, a big sale late in the year — the annualized method can lower the early payments. That’s a Delta conversation.
Withholding is treated as spread evenly across the year — that’s the IRS’s own convention, and it’s why boosting withholding late in the year can fix an underpayment that estimates can’t.
Indiana: quarterly payments target your expected 2026 Indiana tax less withholding. County tax belongs in your Indiana number.
2026 due dates verified: April 15, June 15, September 15 (2026) and January 15 (2027) — all business days.
Not modeled: the annualized-income method, farmer/fisherman special rules, and household-employment taxes.

Want the schedule tied to your real year? That’s literally what we do.

We calculate estimates for our clients as part of every return — sized to the safe harbor, adjusted when the year changes, with exact instructions each quarter. If these numbers made you wince, that’s a sign the plan needs a professional pass.

Reach your Delta team at (260) 440-2747 or info@deltacpagroup.com and we’ll walk through it with you.

We are always happy to talk it through.

Thank you,
Amy Grego, CPA Delta CPA Group, LLC · (260) 440-2747