M-63D-EXT: Entity-Level Tax Extension Payment Worksheet (2025)

Who files this form

This worksheet is for pass-through entities (PTEs) that have elected to pay the Massachusetts PTE Excise and need to calculate an extension payment. The form covers S corporations, partnerships and trusts.

PTE taxpayers receive an automatic six-month filing extension if they pay at least 80% of the tax due for the taxable year by the original return due date. If worksheet line 6 shows no tax due, no further action is needed for the extension.

When it's due

For tax year 2025, the worksheet lists these extension payment deadlines:

• Calendar-year S corporations and partnerships: March 15.
• Calendar-year trusts: April 15.
• Fiscal-year S corporations and partnerships: The 15th day of the third month following the close of the tax year.
• Fiscal-year trusts: The 15th day of the fourth month following the close of the tax year.

If the due date falls on a Saturday, Sunday or legal holiday, use the next regular workday. The full amount on line 6 must be paid by the original return due date.

What you'll need

Have these figures available to complete the worksheet:

• Expected total tax for 2025, from Form 63D-ELT, Calculation section, line 2.
• Massachusetts Entity-Level Tax withheld.
• Any 2024 overpayment applied to your 2025 estimated tax, excluding any 2024 refund.
• Your 2025 Massachusetts estimated tax payments, excluding the overpayment already entered on line 3.

How to file

1. Enter your expected 2025 tax on line 1.
2. Enter withholding, the applied 2024 overpayment and 2025 estimated payments on lines 2 through 4.
3. Add lines 2 through 4 and enter the total on line 5.
4. Subtract line 5 from line 1 and enter the result on line 6, but not less than zero.

If line 6 shows tax due, pay the full amount electronically by the original return due date. You can pay through MassTaxConnect at mass.gov/masstaxconnect. Any PTE making an extension payment must pay electronically.

If line 6 shows no tax due, no further action is needed for the extension.

Common mistakes

• Entering a 2024 refund on line 3: Enter only a 2024 overpayment applied to 2025 estimated tax.
• Counting the same payment twice: Do not include the line 3 amount again on line 4.
• Entering a negative balance on line 6: The amount cannot be less than zero.
• Treating the filing extension as extra time to pay: It does not extend the payment deadline. Interest applies to tax not paid by the original due date.
• Missing the 80% payment requirement: If less than 80% of the tax due is paid by the original return due date, the extension is invalid. Late-return and late-payment penalties and interest are assessed from the original due date.

Questions people ask

How long is the automatic filing extension?

It is six months for PTE taxpayers that meet the payment requirements.

Does paying 80% mean I can wait to pay the rest?

The 80% requirement determines whether the extension is valid. The worksheet still requires the full amount on line 6 to be paid by the original return due date, and interest applies to unpaid tax after that date.

What happens if tax remains unpaid after the extended period?

Tax not paid within the extended period is subject to a penalty of 1% per month, up to 25%, from the extended due date.

Where can I find more information about electronic filing and payment requirements?

The worksheet refers taxpayers to TIRs 16-9 and 21-9.

Official sources

• https://www.mass.gov/lists/dor-tax-forms-and-instructions