Massachusetts

Corporate income tax

Corporate excise (not a pure income tax): returns are due on the 15th day of the fourth month after the end of the taxable year for C corporations (including security corporations, financial institutions and insurance companies) and the 15th day of the third month for S corporations. Excise = 8.0% of net income plus $2.60 per $1,000 of tangible property or net worth, with a $456 minimum excise.

Extension. Automatic extension of time to file (no form) provided the corporation has paid, by the original due date, the greater of 50% of the total tax...

Partnerships and S corporations

S corporations owe an entity-level excise: the $2.60/$1,000 non-income measure ($456 minimum) plus a net-income excise of 2% if total receipts are $6 million or more but under $9 million and 3% if $9 million or more (plus 8% on federally taxable built-in gains/passive income). Separately, PTEs may elect the chapter 63D PTE excise (5% of qualified members' income) and, for tax years beginning on or after Jan 1, 2026, the new chapter 63E PTE excise (4% on income above the surtax threshold), or both; election made on Form 63-ELT (63D-ELT before 2026) with the annual return and is irrevocable.

Sales and use tax

Due date. Form ST-9 returns and payments are due on or before the 30th day following the close of the period (monthly, quarterly or annual). This is the 30-day rule enacted in the FY21 budget effective for periods ending after April 1, 2021; before that returns were due on the 20th.

Filing frequency. Based on reasonably estimated annual sales/use tax liability (exclusive of meals tax): annual if $100 or less; quarterly if $101 to $1,200; monthly if over $1,200. Schedule chosen for the first return is kept for the calendar year and corrected by the Commissioner the following year.

Thresholds. Annual: $100 or less per year. Quarterly: $101 to $1,200 per year. Monthly: more than $1,200 per year.

Prepayments. Advance payment (G.L. c. 62C, s. 16B, beginning April 2021): taxpayers with more than $150,000 in cumulative liability for the tax type in the prior calendar year must pay, by the 25th of each month, either the tax collected from the 1st through the 21st of that month or at least 80% of the prior month's total liability; the balance is due with the return on the 30th of the following month. 5% penalty on underpayment unless the advance payment is at least 70% of the month's total liability (auto-assessed for returns filed on or after July 1, 2025).

Notes

Massachusetts does not have an LLC fee or separate franchise tax; LLCs taxed as partnerships file Form 3 with no entity-level income tax unless they elect the PTE excise. The annual report is a Secretary of the Commonwealth filing and is not covered here. mass.gov blocks non-browser fetches (HTTP 403); pages were read through a real browser session.