The confirmed dates
| Date | Federal | Massachusetts |
|---|---|---|
| October 15, 2026 | Extended 2025 Form 1040 due | Extended 2025 Form 1 or 1-NR/PY due (extension valid only if 80% was paid by April 15, 2026) |
| January 15, 2027 | Fourth 2026 estimated tax payment due | Fourth 2026 estimated tax payment due |
| February 1, 2027 | If you file your 2026 return and pay the full balance by this date, you do not need to make the January 15 payment | No equivalent rule on DOR's estimated tax page |
October 15, 2026: extended 2025 returns
If you extended your 2025 return, both returns are due on October 15, 2026. The federal extension came from Form 4868. The Massachusetts extension was automatic, but only if at least 80% of your 2025 Massachusetts tax had been paid by April 15, 2026. Neither extension gave you more time to pay.
Our page on the October 15 deadline walks through the 80% check, the penalties on each side and what to do if you cannot pay the balance in full.
January 15, 2027: the last 2026 estimated payment
If you pay estimated tax on self-employment income, rental income, investment gains or a pension without enough withholding, the fourth installment for 2026 is due January 15, 2027 on both returns. The earlier 2026 installments were April 15, June 15 (printed as June 16 by DOR) and September 15, 2026.
The federal and Massachusetts rules on how much to pay are not the same, and it is a common place for a Massachusetts return to pick up an underpayment penalty.
| Federal | Massachusetts | |
|---|---|---|
| When estimates are required | Generally, if you expect to owe $1,000 or more after withholding and credits | If the tax not covered by withholding is expected to be more than $400 |
| Amount that avoids the penalty | The smaller of 90% of 2026 tax or 100% of 2025 tax (110% if 2025 AGI was over $150,000, or $75,000 married filing separately) | Generally 80% of the year's tax, or 100% of the prior year's tax if you filed a full 12-month Massachusetts return for that year |
| First-year filers | Prior-year rule available if you had a 12-month prior year | No prior-year safe harbor for first-year filers |
February 1, 2027: the file-early option
The 2026 Form 1040-ES says you do not have to make the January 15, 2027 federal payment if you file your 2026 return by February 1, 2027 and pay the entire balance with it. In practice this suits people whose paperwork is simple and arrives early, since most W-2s and 1099s arrive in late January.
DOR's estimated tax page does not describe the same option for Massachusetts, so plan to make the January 15 Massachusetts payment unless you have confirmed otherwise with DOR.
Spring 2027: how the due date for 2026 returns is set
Individual returns are normally due on April 15 of the following year. The IRS rule is that if the 15th falls on a Saturday, Sunday or legal holiday, the due date moves to the next business day. Massachusetts applies the same idea under its own statute, and Massachusetts holidays matter here: Patriots' Day, the third Monday of April, is a legal holiday in Massachusetts.
That is why returns for tax year 2023 were due April 17, 2024 for Massachusetts filers, on both the Form 1 and the federal return: April 15, 2024 was Patriots' Day and April 16 was Emancipation Day in Washington, D.C. It is also why the belief that Massachusetts always gets extra days is wrong. For tax year 2025, the due date was simply April 15, 2026.
Neither the IRS nor DOR has yet published the due date for 2026 returns. We will add it here when they do. Until then, treat mid-April 2027 as the working assumption and confirm the exact date on the IRS When to File page and DOR's due dates page before you rely on it.
Rule of thumb: the spring due date shifts only when April 15 lands on a weekend or a holiday recognized for that return. It is not later every year.
Putting the dates on your calendar
- October 15, 2026: extended 2025 federal and Massachusetts returns
- January 15, 2027: fourth 2026 estimated payment, federal and Massachusetts
- February 1, 2027: federal file-and-pay-in-full date that replaces the January estimate
- Late January 2027: W-2s and most 1099s arrive; start gathering
- Spring 2027: 2026 returns due; confirm the exact date with the IRS and DOR once published
Where we come in
We prepare federal and Massachusetts individual returns together, and for clients with estimated tax we work out both sets of payments so the Massachusetts 80% rule is not an afterthought. Our page on quarterly estimates for the self-employed covers how to size the payments. Before we start any work, we give you a scope and a price in writing.
Figures on this page were checked against the IRS and Massachusetts sources listed alongside on 28 Sep 2026. They change — confirm the current amount before relying on one.
General information for owner-led businesses, not advice for your specific situation. Tax and accounting rules change, and how they apply depends on facts particular to your business. Talk to us — or to another qualified professional — before acting on anything here.
