Every partnership with a usual place of business in Massachusetts, or one that receives more than $100 in federal gross income during the tax year, must file the Massachusetts Partnership Return of Income, Form 3.1Massachusetts Department of Revenue. Partnerships The return itself is informational. The partnership doesn’t pay income tax on it, but the filing tells the Department of Revenue (DOR) how each partner’s share of Massachusetts source income should be taxed, and it triggers the partnership’s own obligations to withhold on non-resident partners and to pay any elected entity-level excise.
Who Has to File
The filing rule comes from Massachusetts General Laws chapter 62C, section 7, which requires an annual information return from every partnership with a usual place of business in the Commonwealth.2General Court of Massachusetts. Massachusetts General Laws Chapter 62C Section 7 DOR extends that requirement to any partnership receiving more than $100 in federal gross income during the year, even without a physical presence in the state.1Massachusetts Department of Revenue. Partnerships Owning or leasing property in Massachusetts, employing people there, or selling to Massachusetts customers each generally puts a partnership inside the rule.
The obligation stands whether or not the partnership owes tax. Break-even and loss years still need a Form 3 so that partner-level allocations are reported. Skipping the return because “there’s no tax due” is a common and expensive mistake: the late-filing penalty is $5 per day.3Massachusetts Department of Revenue. AP 612 Interest and Penalties
What You Need Before You Start
The core document is Form 3. With it, the partnership prepares a Schedule 3K-1 for each partner showing that partner’s distributive share of income, deductions, and credits. Form 3 and its instructions are on the DOR website.1Massachusetts Department of Revenue. Partnerships
Pull together the partnership’s Federal Employer Identification Number (FEIN), principal business address, entity classification, and a completed federal Form 1065. The federal return is the starting point: Massachusetts income begins with federal ordinary business income and gets adjusted from there. A partnership that doesn’t yet have an EIN can apply through the IRS online, using the Social Security number or taxpayer ID of the responsible party.4Internal Revenue Service. Get an Employer Identification Number
Depending on the partnership’s makeup, several other forms may come into play:
- Form MA NRCR, the Nonresident Composite Return, filed on behalf of qualifying non-resident individual partners.5Massachusetts Department of Revenue. Massachusetts Nonresident Composite Tax Forms
- Form 63D-ELT, the election form for the pass-through entity excise, if the partnership chooses to pay tax at the entity level.6Massachusetts Department of Revenue. Elective Pass-Through Entity Excise
- Form PTE-EX, the exemption certificate members submit when they are exempt from pass-through entity withholding.7Mass.gov. Tax Guide for Pass-Through Entity Withholding
How Massachusetts Income Is Calculated
The starting figure is federal ordinary business income from Form 1065. From there, apply Massachusetts additions and subtractions. Only expense deductions that an individually owned business would be allowed are permitted at the partnership level; deductions an individual claims on Schedule A of the federal 1040 are not.8Commonwealth of Massachusetts Department of Revenue. 2025 Instructions for Massachusetts Partnership Return Form 3
Common additions include state, local, and foreign income taxes deducted federally, interest from non-Massachusetts municipal bonds, and federal bonus depreciation under IRC §168(k), which Massachusetts disallows. A partnership claiming bonus depreciation federally has to run a separate depreciation schedule for the Massachusetts return.
Common subtractions include interest on U.S. government obligations and interest from Massachusetts bank accounts (savings accounts, NOW accounts, and term deposits).
Two other quirks catch filers off guard. Massachusetts does not allow net operating loss carryovers or carrybacks at the partnership or individual level. And licensed marijuana businesses can deduct ordinary business expenses on the Massachusetts return that IRC §280E disallows federally, because Massachusetts decoupled from §280E.8Commonwealth of Massachusetts Department of Revenue. 2025 Instructions for Massachusetts Partnership Return Form 3
Apportioning Income If You Operate in Multiple States
A partnership doing business in more than one state can’t send all of its income to Massachusetts. It applies an apportionment formula. Massachusetts uses a single sales factor: total sales into Massachusetts divided by total sales everywhere.9Massachusetts Department of Revenue. Single Sales Factor Where property or employees sit doesn’t enter the calculation.
Tangible goods are sourced to Massachusetts when the property is delivered to a purchaser in the state. Services are sourced based on where the customer receives the benefit. Multiply the apportionment percentage by the partnership’s modified income to get Massachusetts source income, which then flows into each Schedule 3K-1 and drives the withholding numbers for non-resident partners. Small errors here compound across every partner, so it’s worth double-checking.
Non-Resident Partner Requirements
Partnerships with out-of-state partners have two extra compliance layers: withholding, and the option to file a composite return.
Withholding
A partnership that maintains an office or does business in Massachusetts must withhold state tax from each non-resident member’s share of Massachusetts source income.10Mass.gov. 830 CMR 62B.2.2 Pass-Through Entity Withholding For individuals, estates, and trusts, the rate is the Part B personal income tax rate under MGL chapter 62, currently 5%. Corporate partners use the applicable corporate excise rate under MGL chapter 63.
Certain members are exempt: Massachusetts residents, federally tax-exempt organizations, corporations already filing Massachusetts returns that include their distributive share, and pass-through entities filing their own Massachusetts return. Exempt members claim the exemption by giving the partnership a Form PTE-EX, which the partnership keeps on file.7Mass.gov. Tax Guide for Pass-Through Entity Withholding With no exemption certificate and no other information, the default is to withhold at the personal income tax rate.
The Composite Return Option
Rather than making every non-resident individual partner file a separate Massachusetts return, the partnership can file Form MA NRCR on their behalf.5Massachusetts Department of Revenue. Massachusetts Nonresident Composite Tax Forms The composite return rolls their Massachusetts income and tax into one filing.
Only non-resident individuals can join. Corporate, trust, and other entity partners still handle their Massachusetts obligations on their own. Each electing partner must agree in writing to be included, and that signed agreement should be in hand before the composite return goes in. The Schedule 3K-1 given to each electing partner should show that tax was paid on their behalf.
The Pass-Through Entity Excise Election
Since 2021, Massachusetts partnerships have been able to elect a 5% entity-level excise on the income that would otherwise be taxed at the individual partner level. Each qualified member then gets a refundable credit equal to 90% of their share of the excise the partnership paid. The election is made annually on a timely filed Form 3 and confirmed by filing Form 63D-ELT by the return’s due date, including extensions. Once made, it’s irrevocable for that year, and individual members can’t opt out.6Massachusetts Department of Revenue. Elective Pass-Through Entity Excise
Proposed federal legislation may change the value of this election starting with the 2026 tax year. If enacted, it would eliminate the entity-level deduction for PTE taxes and require the payments to flow through to partners as separately stated items subject to individual SALT deduction limits. The federal benefit would then be substantially reduced or eliminated, so partnerships weighing the election for 2026 should look at how the federal change interacts with the Massachusetts credit before committing.
Filing Deadlines and Extensions
Form 3 is due on the 15th day of the third month after the close of the partnership’s tax year.8Commonwealth of Massachusetts Department of Revenue. 2025 Instructions for Massachusetts Partnership Return Form 3 For calendar-year partnerships filing for tax year 2025, that is March 15, 2026, but because that date falls on a Sunday, the due date shifts to March 16, 2026.11Massachusetts Department of Revenue. Massachusetts DOR Tax Due Dates and Extensions
The partnership gets an automatic six-month extension to file, but only if it has paid at least 80% of its total tax liability by the original due date.12Massachusetts Department of Revenue. AP 604 Extensions of Time to File Tax Returns For calendar-year filers who clear that threshold, the extended date is September 15, 2026.11Massachusetts Department of Revenue. Massachusetts DOR Tax Due Dates and Extensions An extension to file is not an extension to pay. Any estimated balance, including composite tax and withholding, still has to be paid by the original March deadline.
The federal Form 1065 shares the same March 15 date and the same six-month extension window, so plan both together.
How to File and Pay
Massachusetts requires partnership returns to be filed electronically. Form 3, all Schedule 3K-1s, and supporting documents go in through MassTaxConnect or authorized commercial tax software.13Massachusetts Department of Revenue. DOR E-Filing and Payment Requirements Paper filing is only allowed under limited hardship exemptions.
Payments have to be electronic too, either by ACH debit on MassTaxConnect or by electronic funds transfer. Make sure each payment is tied to the right tax period and liability type; composite tax and withholding are tracked separately. Save the MassTaxConnect confirmation for your records.
Penalties and Interest
The late-filing penalty on Form 3 is $5 per day, which adds up quickly if the return is forgotten.3Massachusetts Department of Revenue. AP 612 Interest and Penalties Any unpaid tax, whether from withholding, a composite return, or the PTE excise, accrues interest at the federal short-term rate plus four percentage points, compounded daily. For the first half of 2026, that rate runs between 7% and 8%.14Massachusetts Department of Revenue. TIR 26-2 Interest Rate on Overpayments and Underpayments
These charges land on the partnership, not the individual partners. If the partnership fails to withhold on a non-resident partner’s income, DOR looks to the partnership for the shortfall. A simple compliance calendar helps: track the original filing deadline, the payment deadline, and the extended filing deadline as three separate items, because missing any one of them triggers its own consequence.
Amending a Return
If you find an error after filing, prepare a new Form 3 with the corrected figures and mark the “Amended return” oval. Include every schedule that went with the original return, even ones with no changes, along with a written statement explaining what changed and why. Like the original, an amended return goes in electronically.8Commonwealth of Massachusetts Department of Revenue. 2025 Instructions for Massachusetts Partnership Return Form 3
An amendment can raise or lower reported income. The general window is three years from the date the original was filed. When the changes affect partner allocations, issue corrected Schedule 3K-1s so each partner can update their own Massachusetts return.