355SBC: Small Business Corporation Excise Return (2025)
Massachusetts · Massachusetts DOR · Used for tax years 2025
Form 355SBC is the 2025 Massachusetts Small Business Corporation Excise Return for domestic corporations only. It reports income, assets, liabilities, taxable property or net worth, and payments to calculate the excise due or overpayment. It must be filed electronically; paper re
Who files this form
Form 355SBC is the Small Business Corporation Excise Return for domestic corporations only.
The form states that you are not eligible to file this return if Massachusetts income on line 35 is a loss. The provided text does not give complete filing eligibility rules.
What you'll need
Have these forms and records available to complete the return:
- Corporation information, including the Federal Identification number (FID), federal business code, principal business address, Massachusetts charter date and average number of Massachusetts employees.
- U.S. Form 1120 figures from lines 1c, 3, 26 and 28 for the income section.
- A balance sheet as of the last day of the taxable year, showing assets, liabilities, capital stock and surplus.
- Records of prior-year overpayments applied to this year, estimated tax payments and extension payments. If amending, have the payment amount from the original return.
- Schedule 63-WH, line 14, if reporting corporate excise withheld.
- Information for the income adjustments on lines 30 through 34, including an explanation of any other adjustments.
How to file
File electronically. Paper versions of Form 355SBC will not be accepted.
For electronic filing questions, call 617-887-6367. See the Department of Revenue's electronic filing and payment requirements for more information. The form also refers filers to TIRs 16-9 and 21-9.
Use the whole dollar method for the computation section. The return includes a declaration and signature fields for an appropriate officer and the preparer.
Common mistakes
- Submitting a paper return. The form is e-file only, and paper returns will not be accepted.
- Prorating the minimum excise. Line 5 says the minimum excise cannot be prorated.
- Counting a prior-year overpayment twice. Do not include the amount on line 9a in estimated tax payments on line 9b.
- Using line 9d on an original return. This line is only for payments with the original return when amending.
- Filing this form with a loss on line 35. The form says a loss makes you ineligible to file this return.
Questions people ask
Can I mail a paper Form 355SBC?
No. The form must be filed electronically. Paper returns will not be accepted.
Do I calculate tax on tangible property or net worth?
Follow line 24. If line 24b is .10 or greater, enter line 19e in the computation on line 1 and omit line 25. If line 24b is less than .10, complete line 25 and carry line 25c to the computation on line 2.
Can I apply an overpayment to next year?
Yes. Enter the overpayment on line 10 and the amount to credit to next year on line 11. Subtract line 11 from line 10 to calculate the refund on line 12.
Can DOR discuss the return with my paid preparer?
The form has a box to fill in if DOR may discuss the return with the paid preparer.