Quarterly Tax Due Dates 2026: Federal and PA Deadlines

Disclaimer: This is educational information, not tax advice. Always verify specifics with your CPA or tax advisor. Rates and deadlines can change, and your situation may have nuances only a qualified professional can address.

The Short Version

Quarterly tax due dates for 2026 are the same four dates the IRS uses every year:

• Q1: April 15, 2026 (covers income from January 1 to March 31)
• Q2: June 15, 2026 (covers April 1 to May 31)
• Q3: September 15, 2026 (covers June 1 to August 31)
• Q4: January 15, 2027 (covers September 1 to December 31)

The next deadline is September 15, 2026. If you're self-employed and haven't paid anything toward Q3 yet, that's the date to circle. Miss it and the IRS starts charging interest the very next day.

That's the answer most people came here for. But there's a catch that trips up a lot of business owners: the federal payment isn't the only one due. If you live in Pennsylvania, the state wants a quarterly payment on those same dates, and in most municipalities your local earned income tax is due quarterly too. Three payments, three systems, same deadline. So let's walk through the whole schedule.

The Full 2026-2027 Schedule: Federal, PA State, and Local

Here's every date in one place. Federal payments go to the IRS (Form 1040-ES), Pennsylvania state payments go through myPATH (Form PA-40 ES), and local earned income tax goes to your local collector (Keystone, Berkheimer, or Jordan Tax Service, depending on where you live).

Quarter	Income Period Covered	Federal Due Date	PA State Due Date	PA Local EIT (Self-Employed)
Q1	Jan 1 to Mar 31, 2026	April 15, 2026	April 15, 2026	April 15, 2026
Q2	Apr 1 to May 31, 2026	June 15, 2026	June 15, 2026	June 15, 2026
Q3	Jun 1 to Aug 31, 2026	September 15, 2026	September 15, 2026	September 15, 2026
Q4	Sep 1 to Dec 31, 2026	January 15, 2027	January 15, 2027	January 15, 2027

Notice the quarters aren't even. Q2 covers two months of income while Q3 covers three. The IRS has its own logic here, and no, it doesn't really make sense. Just put the dates on your calendar and don't fight it.

The weekend and holiday rule: when a due date lands on a Saturday, Sunday, or legal holiday, the deadline shifts to the next business day. For 2026, you don't need to worry about it. All four dates fall on regular weekdays, so what you see in the table is what you get.

Who Actually Has to Pay Quarterly

The federal rule is simple: if you expect to owe $1,000 or more in federal tax for the year after subtracting your withholding, the IRS expects you to pay as you go. That covers most sole proprietors, freelancers, LLC members, partners, and S-Corp owners who take distributions. It also catches people with a W-2 paycheck plus 1099 income on the side, because nothing's being withheld on that side income.

And here's the part that saves people: the safe harbor rule. You avoid the underpayment penalty entirely if your four payments add up to either:

• 90% of what you'll owe this year, or
• 100% of what you owed last year (110% if your adjusted gross income was over $150,000)

Most of our clients use the prior-year number. It's a known figure sitting right on last year's return, you divide it by four, and you're protected even if this year turns out to be your best year ever. No guessing required.

What a Missed Payment Actually Costs

The federal penalty for underpaying isn't a flat fine. It works like interest. The IRS charges the federal short-term rate plus 3 percentage points on whatever you should have paid, for every day it's late. Right now that rate is 7% annually, and it accrues day by day until you pay.

So if your Q3 payment should've been $8,000 and you pay it three months late, you're looking at roughly $140 in penalty for that one quarter. Skip all four quarters on a $32,000 tax bill and settle up the following April? Now it's pushing $1,500, because each skipped quarter accrues from its own due date, and that's before Pennsylvania adds its own underpayment interest on the state side.

Is $140 going to sink your business? No. But we've watched this compound over multiple years with new clients who just never knew quarterly payments existed. Two or three years of skipped quarters, federal plus state, and suddenly you've handed the government a couple thousand dollars for nothing. That money bought you no equipment, no marketing, no help. It was pure late fee.

The IRS publishes the payment vouchers, worksheets, and current-year details on the official Form 1040-ES page. That's the source we check every year, because the rate resets quarterly and the worksheets change.

The Pennsylvania Layer: State and Local

Pennsylvania keeps it simple on timing. The state estimated dates mirror the federal schedule exactly: April 15, June 15, September 15, and January 15. The tax itself is a flat 3.07% on earned income, paid through myPATH with Form PA-40 ES. Flat rate, no brackets. Honestly one of the few easy things about PA taxes.

Then there's the local layer, which is the one everybody forgets. If you're self-employed in Pennsylvania, your municipality and school district collect earned income tax (EIT), usually 1% to 3% depending on where you live, and the local collectors expect quarterly payments on the same schedule. Nobody withholds it for you. We wrote a full breakdown of how the local system works, EIT rates and PSD codes included, in our PA local taxes guide (linked below).

And if you want the deep dive on the Pennsylvania side specifically, including how to calculate each payment and a worked example with real dollar amounts, that's here: PA estimated tax deadlines for 2026.

What If You Can't Pay a Quarter?

It happens. A slow summer, a client who pays 60 days late, an equipment repair that ate the tax money. If September 15 shows up and the cash isn't there, don't just skip it and hope.

Pay what you can. The penalty is interest-based, so a partial payment shrinks the amount that's accruing. Paying $5,000 of an $8,000 quarter costs you a lot less than paying zero. And if your income genuinely dropped this year, you may be able to recalculate your payments based on what you're actually earning instead of last year's number.

We covered the full playbook, including the annualized income method and what to say to the IRS, in our guide on what to do when you can't pay your estimated taxes (linked below).

Stop Finding Out in April

Every quarterly tax horror story we've seen starts the same way: the owner didn't know what they'd earned, so they couldn't know what they owed. The deadline wasn't the problem. The books were.

With monthly bookkeeping, your income is tracked in real time, so before each due date you get an actual number instead of a guess. Pair that with tax prep support and your CPA gets clean records with every quarterly payment already documented. We do this for business owners across the Pittsburgh area and for remote clients anywhere in the US.

September 15 is coming either way. If you're not sure what you should be sending, book a free Financial Health Check and we'll figure out your number together. No judgment if you're behind. Getting caught up is kind of our specialty.

Remember: This is educational information, not tax advice. Verify your specific numbers with your CPA before making payments.