State & Local Tax (SALT)

State Tax Deadlines

Massachusetts Tax Deadlines: Individual & Corporate Filing Guide

Massachusetts Tax Deadlines: Individual & Corporate Filing Guide

Priyanka B A

Massachusetts operates on a distinct filing calendar and imposes entity-level compliance beyond federal rules.

Massachusetts Tax Deadlines at a Glance (2026)

Entity Type

Return Due

Extension Deadline

Individuals

April 15, 2026

October 15, 2026

C Corporations

April 15, 2026

October 15, 2026

S Corporations

March 16, 2026

September 15, 2026

Partnerships

March 16, 2026

September 15, 2026

Individuals

Applies to residents, part-year residents, and nonresidents with MA-source income.

Businesses

Massachusetts imposes an entity-level excise tax on corporations and some S corporations.

Fiscal-Year Entities

Due dates follow months after year-end, not calendar alignment.

Estimated Taxes

Required for individuals and corporations exceeding state thresholds.

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