The Next Tax Deadline
Is September 15

Here is a fact that surprises a lot of business owners: no federal estimated tax payment is due on July 15. If “quarterly taxes” followed calendar quarters, one would be. But the IRS schedule has never worked that way. The second payment of 2026 came due on June 15, and the next one is not due until September 15.

That mismatch between the word “quarterly” and the actual calendar catches people every year, in both directions. Some owners scramble to pay something in July that was actually due a month earlier. Others assume they have until October for a payment that lands in mid-September. This post lays out the real 2026 schedule, explains who owes estimated taxes and how much, and gives you a simple system so that September 15 arrives as a calendar entry, not a crisis.

Quarters That Are Not Quarters: The Real 2026 Schedule

The IRS divides the year into four payment periods, but they are not equal three-month blocks. The second period covers only April and May. The third covers June through August. That is why the “Q2” payment was due June 15 and why nothing at all is due in July. Here is the full schedule for the 2026 tax year, published on Form 1040-ES.

If a due date falls on a weekend or federal holiday, it moves to the next business day. None of the remaining 2026 dates do, so September 15 and January 15 are firm.

Who Has to Make These Payments

The U.S. tax system is pay-as-you-go. Employees satisfy that requirement automatically through paycheck withholding. Business owners, in most cases, do not have that machinery working for them, so the IRS expects payments during the year instead of one check in April.

The general federal rule: you must make estimated payments if you expect to owe at least $1,000 in tax for the year after subtracting your withholding and refundable credits, and your withholding and credits will cover less than the safe harbor amounts described below. In practice, that includes most sole proprietors, partners, S‑corporation shareholders, gig workers, landlords with meaningful rental income, and anyone with significant investment income.

How Much to Pay: The Safe Harbor Rules

You do not have to predict your income perfectly. The IRS gives you two safe harbor targets, and hitting either one protects you from an underpayment penalty regardless of what your final bill turns out to be. Pay the smaller of the two.

For most established Virginia small business owners, Option B is the calmer choice: divide a known number by four, schedule the payments, and stop thinking about it. Option A rewards you in a down year but requires an honest running estimate of current-year profit, which is exactly the kind of number a monthly financial review produces. If your income arrives unevenly, the IRS also allows an annualized installment method that matches payments to when income was actually earned, computed on Form 2210.

What Underpaying Actually Costs in 2026

The underpayment penalty works like interest, not like a flat fine. The IRS sets the rate each quarter at the federal short-term rate plus 3 percentage points, compounded daily. For the quarter that began July 1, 2026, the rate is 7%, up from 6% in the second quarter of the year.

Two details make this more expensive than it sounds. First, the penalty is assessed per payment period: a shortfall on the June 15 payment starts accruing on June 16, even if you catch up in full by September. Second, because it compounds daily, the effective cost of carrying a shortfall for months is higher than the stated annual rate suggests. There is no getting the money back later. It is pure cost.

Virginia Runs Its Own Schedule, and It Is Different

Federal is only half the job. The Virginia Department of Taxation requires its own estimated payments on Form 760ES, and the rules do not mirror the federal ones. Three differences matter most for Virginia owners.

Note the table's first row carefully if 2026 is your first year making estimated payments: a Virginia owner who copied the federal calendar into their reminders would have paid Virginia two weeks early in the spring, which is harmless, but an owner who assumes the two systems always match may eventually get burned by the rules that do differ. Like the federal deadline, Virginia's January 15 payment can be skipped if you file your 2026 Virginia return and pay in full by March 1, 2027.

The System That Makes September 15 Painless

Mid-July is the ideal moment to build this. You are two weeks into the third payment period, June's books are closeable, and there are two full months of runway before the deadline. Here is the system we recommend.

1. Pick your safe harbor target and write it down

   Pull the total tax line from your 2025 federal and Virginia returns. Decide now whether you are paying to the prior-year number or to 90% of a current-year estimate, and note the resulting per-payment amounts for September 15 and January 15.

2. Open a separate tax account and fund it monthly

   Move a fixed percentage of every month's profit, commonly 25% to 30% for combined federal and state obligations, into an account you do not touch. The percentage that fits your situation depends on your margins and entity structure; your monthly P&L review, covered in Monday's post, is where you sanity-check it.

3. Schedule the payments in advance

   EFTPS lets you queue the remaining federal payments in a single session. Virginia's online individual payment system supports future-dated payments as well. A scheduled payment cannot be forgotten in a busy week.

4. Re-check the estimate after Q3 closes

   When September's books close, compare year-to-date profit against the assumption behind your payments. If the year is running meaningfully hotter or colder, adjust the January 15 payment rather than discovering the gap in April.

Where This Series Goes Next

This post covered the schedule, the safe harbors, and the system. Two deeper questions remain: how tax planning differs from tax preparation, and how to build the plain-English calculation for your specific entity type. Both are the subject of Arc 2, Tax Intelligence, which begins Monday, July 27. And when September 15 itself arrives, we will be back with a deadline-day post anchored to the real date, alongside the year-end tax calendar.

References