1099 Contractor in Massachusetts with a California Client: Where Do You File?
Answer
Massachusetts taxes all of it; California taxes only what you earn on its soil. Nothing is withheld from a 1099, so you pay Massachusetts quarterly. A California client alone creates no California filing obligation — performing services inside California does, and Massachusetts then credits that tax.
Last verified
The client's location is the wrong thing to track. What matters is where you were sitting when you did the work — which is why a contractor's exposure to California is measured in days on the ground rather than in invoices sent.
California publishes no de minimis day count or dollar floor for nonresidents. Any California-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 California Franchise Tax Board nonresident instructions before filing.
What you file
- 1Quarterly estimated payments · Massachusetts
Make quarterly estimated payments to Massachusetts Department of Revenue on your full self-employment income — nothing is withheld from a 1099.
- 2Nonresident return · CaliforniaForm 540NR
File a California nonresident return only if you performed services inside California. California publishes no de minimis day count or dollar floor for nonresidents. Any California-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 California Franchise Tax Board nonresident instructions before filing.
- 3Resident return · MassachusettsSchedule OJC
File the Massachusetts resident return last and claim the credit for any tax paid to California.
The two states, side by side
| Massachusetts | California | |
|---|---|---|
| Taxes wages | Yes — flat | Yes — graduated |
| Reciprocity partners | None | None |
| Convenience rule | No | No |
| Nonresident return | Form 1-NR/PY | Form 540NR |
| Credit for other-state tax | Schedule OJC | Schedule S |
| Nonresident safe harbour | None published | None published |
| Local income tax | No | No |
| Revenue department | Massachusetts Department of Revenue | California Franchise Tax Board |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in California and working in Massachusetts 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: Massachusetts → CaliforniaBoth states — credit offsets the double tax
- Remote worker: Massachusetts → CaliforniaHome state only
- Moved mid-year: Massachusetts → CaliforniaTwo part-year returns
Other Massachusetts pairs
Questions people actually ask
I live in Massachusetts and my client is in California. Do I have to file a California tax return?
Massachusetts taxes all of it; California taxes only what you earn on its soil. Nothing is withheld from a 1099, so you pay Massachusetts quarterly. A California client alone creates no California filing obligation — performing services inside California does, and Massachusetts then credits that tax.
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 Massachusetts and California hold an agreement makes no difference to a self-employed filer — sourcing rules decide the answer instead.
How current is this?
The Massachusetts and California rules on this page were last checked against Massachusetts Department of Revenue and California Franchise Tax Board 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.
- Massachusetts Department of Revenue — individual income taxaccessed 2026-08-07
- California Franchise Tax Board — individual income taxaccessed 2026-08-07