While the IRS grants an automatic six‑month extension on Form 1040 when you file Form 4868 by April 15, state income tax extension rules vary widely. California and New York impose their own requirements, whereas Florida and Texas—lacking personal income taxes—have no individual‑return extension to align. Understanding each jurisdiction’s rules can help you avoid penalties and coordinate filing strategies.
Federal Extension Overview
The federal automatic extension moves your filing deadline from April 15 to October 15 when you timely submit Form 4868 and pay any estimated tax due. Note that extensions defer only the filing date—not payment of tax; interest and late‑payment penalties accrue from April 15.
California (CA)
California does not accept the federal extension automatically. Individual filers must use Form 3519 (Payment for Automatic Extension for Individuals) to request an extension. Key points include:
- Deadline: File Form 3519 by April 15 and pay at least 90% of the estimated California tax due.
- Extended Due Date: October 15 (six‑month extension) for filing the return.
- Payment Requirement: No extension is granted unless the 90% payment accompanies Form 3519.
- Separate Form 3539: Corporations use Form 3539 by the original due date to extend to October 15.
New York (NY)
New York State and New York City allow individuals to leverage the federal extension but impose conditions on payments. To extend:
- Attach Federal 4868: Include a copy of your approved Form 4868 with Form IT‑370 (Application for Automatic Six‑Month Extension for Individuals).
- Estimated Tax Payment: Pay at least 100% of the prior year’s tax liability (or 90% of current year’s) by April 15.
- Extended Due Date: October 15, aligning with the federal extension.
- NYC Residents: Must also file Form EXT‑02 and satisfy similar payment requirements for city tax.
Florida (FL)
Florida imposes no individual income tax; therefore, there is no state extension for personal returns. Residents need only focus on their federal deadlines. For corporations, Florida’s corporate income/franchise tax uses Form F‑1120EXT, due by the original return date to extend by six months.
Texas (TX)
Texas also has no personal income tax, so individual filers have no state extension requirements. Texas entities subject to franchise tax must request an extension via Form 05‑164 (Request for Extension of Time To File Report), filed by the original due date to obtain a six‑month extension.
Comparison Summary
| Jurisdiction | Individual Extension Form | Payment Requirement | Extended Deadline |
|---|---|---|---|
| Federal | Form 4868 | Estimate tax due | October 15 |
| California | Form 3519 | 90% estimated tax | October 15 |
| New York | Form IT‑370 (attach 4868) | 100% prior‑year or 90% current | October 15 |
| Florida | Not applicable | — | — |
| Texas | Not applicable | — | — |
Best Practices
- Plan Early: Confirm state extension forms and payment thresholds by March.
- Coordinate Payments: Align estimated payments with both federal and state requirements to secure extensions.
- Retain Proof: Save copies of filed extension forms and payment confirmations.
- Monitor Changes: State extension rules can change annually—review guidance each tax season.
Conclusion
California and New York require specific extension forms and payment thresholds to mirror federal deadlines, whereas Florida and Texas have no individual income tax extensions. By understanding each jurisdiction’s rules and syncing your filings and payments, you can avoid penalties and streamline your compliance for the 2025–26 tax season.
