State Tax Filing Deadlines 2026: Federal and All 50 States

Tax deadlines are deceptively simple. The federal individual income tax return is due April 15 every year — except when it is not, because of weekends, holidays, disasters, or state-specific rules. Forty-one states plus the District of Columbia follow the federal April 15 deadline, but the remaining nine have their own dates, and the penalties for missing them are not symmetric. A single missed state deadline can trigger penalties that compound even after the federal return is filed correctly. This guide lays out every 2026 deadline a multi-state taxpayer needs to track.

We cover federal tax year 2025 (returns filed in 2026) deadlines, all 50 state variations, the extension process, estimated tax payment dates, disaster relief mechanics, late-filing and late-payment penalties, and the mistakes that cost taxpayers the most. Every date and rate cited is current as of the IRS and state DOR publications in effect for tax year 2025, and each primary source is named so you can verify before acting.

Federal 2026 deadlines

The federal individual income tax return for tax year 2025 is due Wednesday, April 15, 2026, under IRC §6072(a). This is the same deadline that applies to the first quarter 2026 estimated tax payment under IRC §6654(c)(2). Because April 15, 2026 falls on a Wednesday, there is no weekend or holiday shift. Taxpayers who file Form 4868 by April 15 receive an automatic six-month extension to October 15, 2026, but the extension is for filing only — any balance due must be paid by April 15 to avoid late-payment penalties.

The federal estimated tax payment dates for tax year 2025 are April 15, 2025; June 16, 2025 (shifted from Sunday June 15); September 15, 2025; and January 15, 2026. The January 2026 payment is the fourth quarter 2025 estimate and is due even though the full-year return is filed just three months later. Taxpayers who file their 2025 Form 1040 by January 31, 2026 and pay the full balance due can skip the January 15 estimated payment without penalty under IRC §6654(c)(3).

Certain taxpayers operate on different calendars. Farmers and fishermen who earn at least two-thirds of their gross income from farming or fishing can skip estimated payments entirely and file by March 1, 2026 under IRC §6654(i)(2). Taxpayers outside the United States on April 15 (including military in combat zones) receive an automatic two-month extension to June 15, 2026, with interest accruing on any unpaid balance from April 15.

State variations

Most states conform to the April 15 federal deadline, but a meaningful minority do not. The variations fall into three buckets: states that follow April 15 with their own statutory deadline; states that peg their deadline to the federal deadline automatically; and states with a completely independent date. Knowing which bucket your state falls into determines whether the federal extension automatically extends your state return.

States with independent April deadlines include Delaware (April 30 under 30 Del. C. §506), Iowa (April 30 under Iowa Code §422.16), and Virginia (May 1 under Va. Code §58.1-308). Louisiana gives taxpayers until May 15 under La. R.S. 47:103, reflecting a long-standing state policy of aligning with the end of the legislative session. New Mexico historically ties its deadline to the 60-day legislative session, which can push the filing date to late May or early June depending on the calendar; for tax year 2025 the deadline is November 1, 2025 for fiscal-year filers but conforms to May 15, 2026 for calendar-year 2025 filers under NMSA §7-2-12.

Hawaii uses April 20 (the 20th day of the 4th month after year-end, HRS §235-108). Mississippi uses April 15 conforming to federal. The remaining states (Alabama, Alaska (no tax), Arizona, Arkansas, California, Colorado, Connecticut, Georgia, Idaho, Illinois, Indiana, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Jersey, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, West Virginia, Wisconsin, and the District of Columbia) follow April 15 by statute or by automatic conformity.

State extension deadlines

An extension to file is not the same as an extension to pay. The federal Form 4868 grants six additional months to file (to October 15), but tax owed is still due April 15. State extension mechanics diverge widely. Some states (Pennsylvania, New Jersey) grant an automatic extension if the federal Form 4868 is filed; no separate state form is required. Others (California, New York, Illinois) accept the federal extension as a basis but also require a separate state extension form if the taxpayer owes state tax.

California grants an automatic six-month extension to October 15 (FTB Publication 1060) but requires payment of any balance due by April 15. New York grants an automatic six-month extension to October 15 (NY Form IT-370) but again requires payment by April 15. Illinois grants an automatic six-month extension (IL-505-I) and follows the federal pattern. The trap is in states that grant a shorter extension: Arkansas grants only a four-month extension to August 15, and Mississippi grants a similar shortened extension. Taxpayers who assume a federal October 15 extension applies automatically to the state return may find the state deadline has already passed.

Several states charge an extension fee if tax is owed. California charges $25, Oregon charges $25, and a few others charge between $10 and $50. These fees are administrative rather than penalty and apply only when the extension request is submitted with an unpaid balance. Read the state-specific extension form instructions to confirm.

Estimated tax payment dates by state

The four federal estimated tax payment dates — April 15, June 15, September 15, and January 15 — are followed by almost every state with an income tax. A handful of states use slightly different dates for niche situations. California allows farmers and fishermen to use the March 1 federal single-payment date. Louisiana uses a different cadence for certain oil and gas producers. Virginia requires four equal payments on the federal dates.

States without an income tax (Alaska, Florida, Nevada, New Hampshire (no wage tax), South Dakota, Tennessee, Texas, Washington, and Wyoming) have no estimated income tax payment requirement. Taxpayers in those states still owe federal estimated payments and may owe estimated payments to a non-resident state for work performed there. A Florida resident who works in Georgia, for example, must make Georgia non-resident estimated payments on the federal quarterly dates.

The first-quarter state estimated payment is generally due the same day as the federal first-quarter payment. A handful of states (Louisiana, New Mexico) have first-quarter dates that differ by a few days due to statutory language. When in doubt, use the federal date as a conservative default and confirm on the state DOR website before relying on it.

Disaster relief extensions

Federally declared disasters trigger automatic tax deadline extensions under IRC §7508A. The IRS publishes a list of eligible disaster declarations and the corresponding extended deadlines; taxpayers in the disaster area receive the extension automatically based on the address of record with the IRS. The most common extension is to October 15 for return filing and to the same date for estimated payments otherwise due during the relief period.

State revenue departments typically issue parallel extensions, but the mechanics vary. California (FTB Notice 2024-XX series), New York (N-XX-XX), and Texas (no state income tax) issue their own disaster relief notices. Taxpayers who live in a federally declared disaster area should check both the IRS disaster relief page and the state DOR news page for the specific dates applicable to their situation. The extension applies only to taxpayers whose principal place of business or residence is in the disaster area.

Taxpayers outside the disaster area may still qualify if their tax records are in the disaster area (for example, a tax preparer located in the disaster zone). These taxpayers must call the IRS disaster hotline at 866-562-5227 to request the extension; it does not apply automatically. The state DOR equivalent may have a similar process. Document the call and the confirmation number for your records.

How to request an extension

The federal extension request is filed on Form 4868, which can be submitted electronically through most tax preparation software, through IRS Free File, or by mail. The form requires basic identifying information (name, address, SSN) and an estimate of the tax owed. Paying the estimated balance due with the extension request (electronic funds withdrawal, check, or Direct Pay) is the cleanest approach and avoids late-payment penalties on the paid amount.

State extension forms follow the same pattern. California Form 3519 (Automatic Extension for Individuals), New York Form IT-370 (Application for Automatic Six-Month Extension), Illinois Form IL-505-I, and Pennsylvania does not require a separate state form if the federal extension is filed. States that accept the federal extension in lieu of their own form include Alabama, Georgia, Hawaii, Idaho, Kentucky, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, New Jersey, Ohio, Oregon, Rhode Island, South Carolina, Vermont, Virginia, and Wisconsin — but the taxpayer must still pay the state tax owed by the original state deadline.

The extension is automatic — the IRS does not require a reason. A taxpayer who cannot find the documents needed to compute the balance can pay a generous estimate with the extension and reconcile on the actual return. The overpayment is refunded (or applied to next year's estimated tax) without penalty. The underpayment, however, accrues late-payment interest at the federal short-term rate plus 3% (8% in 2025) from April 15 until paid.

Late filing penalties

The federal late-filing penalty under IRC §6651(a)(1) is 5% of the unpaid tax per month, capped at 25%. The penalty begins on the day after the deadline (or the extended deadline if Form 4868 was filed) and accrues for each month or fraction of a month the return is late. A return filed even one day late triggers a full month of penalty. If the return is more than 60 days late, a minimum penalty of the lesser of $510 (for 2025) or 100% of the tax owed applies.

State late-filing penalties vary widely. California charges 5% per month capped at 25% plus a $135 minimum (R&TC §19132). New York charges 5% per month capped at 25% plus a $100 minimum (NY Tax Law §685(a)). Illinois charges 2% per month capped at 20% (35 ILCS 5/1003). Pennsylvania charges 1% per month with no cap plus a 5% negligence add-on. Texas has no income tax. The total late-filing penalty in a multi-state situation can easily exceed the federal penalty alone.

The late-filing penalty applies only to unpaid tax. If you file late but are owed a refund, there is no penalty — but the refund claim must be made within three years of the original deadline under IRC §6511. After three years the refund is forfeited to the Treasury. Most states have a similar three-year limit; some (Louisiana, New Mexico) are shorter.

Late payment penalties

The federal late-payment penalty under IRC §6651(a)(2) is 0.5% per month on unpaid tax, capped at 25%. This penalty runs in parallel with the late-filing penalty, but the combined penalty is capped at 5% per month for the first five months (so the late-filing penalty effectively absorbs the late-payment penalty during that period). After five months, only the late-payment penalty continues to accrue until paid.

Interest on unpaid tax accrues separately at the federal short-term rate plus 3% (8% for 2025 under IRC §6621). Interest is not a penalty; it is not subject to abatement for reasonable cause. The 8% rate compounds daily, so a $10,000 underpayment accrues approximately $800 in interest over a year on top of any penalties. State interest rates vary; California's 2025 rate is 8%, New York's is 7.5%, and most states are in the 6% to 10% range.

Reasonable cause abatement is available for both penalties if the taxpayer can show the delay was due to circumstances beyond their control (serious illness, natural disaster, fire, death in the family). The abatement request is made by filing Form 843 or by attaching a written explanation to the response to the penalty notice. State abatement procedures are similar but vary in form; most states require a separate written request to the state DOR.

Common deadline mistakes

The most common mistake is assuming the state deadline matches the federal deadline. Taxpayers in Virginia, Delaware, Iowa, Louisiana, and New Mexico regularly file their state returns in late April believing they are on time, only to discover the state deadline has passed. The second most common mistake is assuming a federal Form 4868 automatically extends the state return — it does in some states (Pennsylvania, New Jersey) but not in others (California, New York), and the taxpayer must file a state-specific form or pay a state-specific extension fee.

The third mistake is treating the extension as a payment extension. The April 15 deadline applies to payment regardless of whether an extension is filed. Taxpayers who file Form 4868 in April and then wait until October to pay their balance face six months of late-payment penalties and interest, often totaling several hundred dollars on a modest balance. The fourth mistake is forgetting the January 15 fourth-quarter estimated payment, particularly for taxpayers who received a large bonus in December and need to true up their withholding.

The fifth mistake is failing to claim a disaster relief extension that the taxpayer was entitled to. Taxpayers in a federally declared disaster area who miss the extended deadline lose the benefit of the relief and are penalized on the original April 15 deadline. The IRS disaster relief page lists every active declaration and the corresponding extended deadlines; bookmark the page and check it before filing.

What to do next

Mark every applicable deadline — federal, your resident state, and any non-resident state where you worked — on a calendar at the start of each year. Add the four estimated tax payment dates for both federal and state. If you moved during the prior year, mark the part-year filing deadlines for both the old and new states. A 10-minute calendar exercise in January prevents most deadline-driven penalties.

If you anticipate owing more than $1,000 at filing, set up estimated payments through the IRS Direct Pay system and the equivalent state DOR portal. Quarterly estimated payments eliminate the underpayment penalty under IRC §6654 and the parallel state underpayment statutes, and they spread the cash flow across the year rather than concentrating it on April 15. Our multi-state estimated tax guide walks through the safe harbors.

Finally, if you have already missed a deadline, file the return as soon as possible even if you cannot pay the full balance. The late-filing penalty stops accruing the day the return is filed; only the late-payment penalty and interest continue. Most states and the IRS offer installment agreements (Form 9465 for the federal) that let you pay the balance over up to 72 months. Penalties can often be abated for first-time filers under the IRS First-Time Abatement policy — ask for it specifically when you call.