Quarterly Estimated Taxes Are quarterly estimated taxes equal?

The four periods aren't the same length

Quarterly estimated taxes cover four periods. On a calendar year, April 15 covers January through March. June 15 covers April and May. September 15 covers June through August. January 15 of the next year covers September through December.

That's three months, then two, then three, then four. A business with a busy holiday season often earns the most in that last four-month stretch. A landscaper or a pool company may earn most of its money in spring and summer.

When four equal payments are right

Under the regular method, each payment is one-fourth of the amount you need to pay for the year. The length of the periods doesn't change that. If you're paying 100 percent of last year's total tax, four equal payments are exactly what the IRS expects.

Here's a made-up example. Last year's total tax was $32,000, and adjusted gross income was $190,000. Because that's over $150,000, the safe harbor is 110 percent of last year's tax, or $35,200. That's $8,800 on each of the four dates, even though June covers only two months.

Equal payments also work when you base them on 90 percent of this year's tax, as long as that estimate is accurate. The trouble comes from estimates that are really guesses. That's why we check your books before we use this year's numbers.

When your payments can be uneven

If most of your income comes late in the year, equal payments can mean paying more early on than you need to. The annualized income installment method lets each payment follow the income you've actually earned by that point.

Each annualized period starts on January 1. The first runs through March 31, the second through May 31 and the third through August 31. The last one covers the whole year. A slow spring can mean smaller April and June payments, with more due in September and January.

You figure this on Schedule AI and file Form 2210 with your return. It takes accurate books for each period, so we use it once your books are caught up, and we can help you get them there.

How we work out your payments

On a call, we go through the four periods and figure out which one you're in. Then we ask whether last year's return is filed. If it is, we usually start with that total tax. If this year is much slower or busier, we look at your books before we change course.

If you have last year's return, keep it open during the call. If this is your first year in business, tell us that too. Your personal return from last year still counts, even if the business is new. For a short list of the dates, see quarterly estimated tax due dates. When you're ready to send a payment, the page on how to pay federal estimated taxes shows the free ways to do it.

Questions owners ask about the April payment

Do I have to finish my March books before I pay in April? No. If last year's return is filed, its total tax is enough to set the April payment. You can catch up your March books afterward.

What if a due date falls on a weekend? Your payment is on time if you make it the next business day. In 2026, April 15 was a Wednesday, so that didn't come up. January 15, 2028 is a Saturday, so that payment will move to the next business day.

Can the annualized method still help if I didn't plan for it? Yes. If your income turned out uneven, Schedule AI can lower or remove a penalty when you file, even if you paid in equal amounts during the year.

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