New York is one of the most complex state jurisdictions, layering an Article 9-A franchise tax, an elective pass-through entity tax (PTET), the MTA surcharge, and NYC-level taxes on top of personal income tax. Precision on which taxes are elective versus mandatory matters here.
New York Tax Deadlines at a Glance (2026)
Entity Type | Return Due | Extended Due Date |
|---|---|---|
Individuals | April 15, 2026 | October 15, 2026 (Form IT-370) |
C Corporations (Article 9-A) | April 15, 2026 | October 15, 2026 (Form CT-5) |
S Corporations | March 16, 2026 | September 15, 2026 |
Partnerships | March 16, 2026 | September 15, 2026 |
Personal extensions use Form IT-370 for an automatic six-month extension; corporations use Form CT-5. In both cases tax owed is still due by the original date — pay roughly 90% to avoid penalties.
The PTET Is Elective, Not Mandatory
A frequent misconception: New York’s PTET is optional, not mandatory. Eligible partnerships and New York S corporations annually elect to pay it, and the election window closes March 15. Electing entities make estimated PTET payments on March 15, June 15, September 15, and December 15, and the annual PTET return is due March 15. New York City maintains a separate NYC PTET that CPAs advising city businesses should evaluate alongside the state election.
MTA Surcharge and MCTMT
Two distinct Metropolitan Commuter Transportation District taxes get conflated. The MTA surcharge (Form CT-3-M) is an add-on to the Article 9-A franchise tax for corporations doing business in the 12-county MCTD. The MCTMT is a separate payroll/self-employment tax; self-employed individuals with net MCTD earnings above $50,000 are subject to it. They are different taxes on different bases — don’t merge them on a client’s calendar.
Estimated Payments and Penalties
Individual estimated tax (Form IT-2105) is due April 15, June 15, September 15, 2026, and January 15, 2027, required if you expect to owe more than $300 after withholding. The late-filing penalty is 5% of tax due per month (max 25%); the late-payment penalty is 0.5% per month (max 25%). Statutory underpayment interest carries a floor of 7.5%, adjusted quarterly and compounded daily.
CPA Action Steps
Decide and file the elective PTET by March 15 — it is not automatic
Evaluate the separate NYC PTET for city clients
Separate the corporate MTA surcharge (CT-3-M) from the MCTMT payroll tax
Calendar the four IT-2105 estimated dates
Confirm current rates and the MTA-surcharge percentage against the NY Department of Taxation and Finance (tax.ny.gov) before filing.