Massachusetts Self-Employed — Schedule C, Form 1, & SE Tax

Establish the taxpayer's Massachusetts residency status (full-year resident, part-year resident, or non-resident) and confirm the business structure. Residency determines whether Form 1 or Form 1-NR/PY applies and whether worldwide or only Massachusetts-source self-employment income is taxable. Statutory residency (domicile OR 183+ days with a permanent place of abode) must be confirmed before any income is allocated.

Compile gross receipts, cost of goods sold, and allowable deductions for the federal Schedule C. Compute net self-employment income and the Schedule SE tax (15.3% on net earnings up to the Social Security wage base, 2.9% above). The deductible half of SE tax flows to federal Form 1040 Schedule 1 and also reduces Massachusetts Part B income. Confirm whether the taxpayer received any Form 1099-NEC or 1099-K that must be reconciled.

Apply Massachusetts-specific adjustments to the federal Schedule C result. Massachusetts decouples from federal §168(k) bonus depreciation — any bonus depreciation claimed federally must be added back on Schedule E-1 of the Massachusetts return, and MACRS depreciation is substituted. Massachusetts also decouples from the federal §199A QBI deduction (not applicable to individuals, but relevant if the taxpayer holds a pass-through interest). Confirm whether any PFML self-employed contributions were made (self-employed individuals may voluntarily opt into the Massachusetts PFML program under M.G.L. c. 175M, and contributions are deductible at the state level).

Massachusetts taxes short-term capital gains (assets held one year or less) at 8.5% under Part A, compared to the federal rate. Long-term capital gains are taxed at 5% (Part C). Aggregate all Part A, Part B, and Part C taxable income to determine whether the taxpayer crosses the 2025 Fair Share Amendment surtax threshold of $1,083,150 — above which an additional 4% applies to the excess. Self-employed taxpayers who realized asset sales, received installment payments on prior-year sales, or had collectibles gains must compute each bucket carefully.

Self-employed Massachusetts taxpayers who expect to owe more than $400 in state tax must make quarterly estimated payments on Form 1-ES. The due dates are April 15, June 15, September 15, and January 15. Safe harbors are 80% of current-year Massachusetts tax or 100% of the prior year's Massachusetts tax (110% if prior-year Massachusetts AGI exceeded $150,000). Reconcile any estimated payments already made against the computed liability and confirm the fourth-quarter installment due January 15.

Assemble the complete Massachusetts Form 1 (or 1-NR/PY), attach all required schedules, and confirm the balance due or refund. Verify whether the self-employed taxpayer's business activity creates a Massachusetts sales tax collection obligation — Massachusetts imposes a 6.25% sales tax on SaaS, digital goods, and canned software sold to Massachusetts customers, and a $100,000 economic nexus threshold applies. Confirm the April 15 filing deadline (or request a 6-month automatic extension on Form M-4868, with payment of any estimated balance due to avoid penalties).