1099 Contractor in South Carolina with a Massachusetts Client: Where Do You File?
Answer
Two possible returns, one certainty. The certainty is South Carolina, which taxes residents on all self-employment income and expects quarterly estimated payments. The possibility is Massachusetts, which taxes nonresidents on services actually performed inside the state — invoices sent there do not count.
Last verified
Reciprocity agreements are the first thing contractors ask about and the first thing that does not apply to them. Every agreement in the country is a wage-withholding arrangement, and a 1099 has no withholding to switch off.
Massachusetts publishes no de minimis day count or dollar floor for nonresidents. Any Massachusetts-source wage income above the state's general filing threshold requires a nonresident return, and that threshold is reset each year — check the current figure on the Massachusetts Department of Revenue nonresident instructions before filing.
What you file
- 1Quarterly estimated payments · South Carolina
Make quarterly estimated payments to South Carolina Department of Revenue on your full self-employment income — nothing is withheld from a 1099.
- 2Nonresident return · MassachusettsForm 1-NR/PY
File a Massachusetts nonresident return only if you performed services inside Massachusetts. Massachusetts publishes no de minimis day count or dollar floor for nonresidents. Any Massachusetts-source wage income above the state's general filing threshold requires a nonresident return, and that threshold is reset each year — check the current figure on the Massachusetts Department of Revenue nonresident instructions before filing.
- 3Resident return · South CarolinaForm SC1040TC
File the South Carolina resident return last and claim the credit for any tax paid to Massachusetts.
The two states, side by side
| South Carolina | Massachusetts | |
|---|---|---|
| Taxes wages | Yes — graduated | Yes — flat |
| Reciprocity partners | None | None |
| Convenience rule | No | No |
| Nonresident return | Form SC1040 with Schedule NR | Form 1-NR/PY |
| Credit for other-state tax | Form SC1040TC | Schedule OJC |
| Nonresident safe harbour | None published | None published |
| Local income tax | No | No |
| Revenue department | South Carolina Department of Revenue | Massachusetts Department of Revenue |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in Massachusetts and working in South Carolina gives:Home state, plus the client state if you work there.
Same two states, different situation
The withholding answer turns on how you are paid and where the work happens, not only on which two states are involved.
- W-2 commuter: South Carolina → MassachusettsBoth states — credit offsets the double tax
- Remote worker: South Carolina → MassachusettsHome state only
- Moved mid-year: South Carolina → MassachusettsTwo part-year returns
Other South Carolina pairs
Questions people actually ask
I live in South Carolina and my client is in Massachusetts. Do I have to file a Massachusetts tax return?
Two possible returns, one certainty. The certainty is South Carolina, which taxes residents on all self-employment income and expects quarterly estimated payments. The possibility is Massachusetts, which taxes nonresidents on services actually performed inside the state — invoices sent there do not count.
Do reciprocity agreements help a 1099 contractor?
No. Every state reciprocity agreement in the country is an arrangement about wage withholding between two revenue departments, and a 1099 has no withholding to switch off. Whether South Carolina and Massachusetts hold an agreement makes no difference to a self-employed filer — sourcing rules decide the answer instead.
How current is this?
The South Carolina and Massachusetts rules on this page were last checked against South Carolina Department of Revenue and Massachusetts Department of Revenue on 2026-08-07. We re-check the full grid every December after state legislative sessions close, and re-check the convenience-of-the-employer states quarterly because that is where the rules move fastest.
Sources
Every fact above comes from the revenue department that publishes the rule. We do not cite secondary summaries, and we do not restate a figure we could not find at source.
- South Carolina Department of Revenue — individual income taxaccessed 2026-08-07
- Massachusetts Department of Revenue — individual income taxaccessed 2026-08-07