1099 Contractor in Connecticut with a Missouri Client: Where Do You File?
Answer
Connecticut always, Missouri sometimes. With no withholding on a 1099 the whole tax is yours to manage: estimate to Connecticut through the year, and file a Missouri nonresident return for any income from work you physically performed in Missouri, claiming the credit back on the Connecticut return.
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 Missouri is measured in days on the ground rather than in invoices sent.
Missouri publishes no de minimis day count or dollar floor for nonresidents. Any Missouri-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 Missouri Department of Revenue nonresident instructions before filing.
What you file
- 1Quarterly estimated payments · Connecticut
Make quarterly estimated payments to Connecticut Department of Revenue Services on your full self-employment income — nothing is withheld from a 1099.
- 2Nonresident return · MissouriForm MO-1040 with Form MO-NRI
File a Missouri nonresident return only if you performed services inside Missouri. Missouri publishes no de minimis day count or dollar floor for nonresidents. Any Missouri-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 Missouri Department of Revenue nonresident instructions before filing.
- 3Resident return · ConnecticutSchedule 2 (Form CT-1040)
File the Connecticut resident return last and claim the credit for any tax paid to Missouri.
The two states, side by side
| Connecticut | Missouri | |
|---|---|---|
| Taxes wages | Yes — graduated | Yes — graduated |
| Reciprocity partners | None | None |
| Convenience rule | Only against convenience-rule states | No |
| Nonresident return | Form CT-1040NR/PY | Form MO-1040 with Form MO-NRI |
| Credit for other-state tax | Schedule 2 (Form CT-1040) | Form MO-CR |
| Nonresident safe harbour | None published | None published |
| Local income tax | No | Yes |
| Revenue department | Connecticut Department of Revenue Services | Missouri Department of Revenue |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in Missouri and working in Connecticut 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: Connecticut → MissouriBoth states — credit offsets the double tax
- Remote worker: Connecticut → MissouriHome state only
- Moved mid-year: Connecticut → MissouriTwo part-year returns
Other Connecticut pairs
Questions people actually ask
I live in Connecticut and my client is in Missouri. Do I have to file a Missouri tax return?
Connecticut always, Missouri sometimes. With no withholding on a 1099 the whole tax is yours to manage: estimate to Connecticut through the year, and file a Missouri nonresident return for any income from work you physically performed in Missouri, claiming the credit back on the Connecticut return.
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 Connecticut and Missouri hold an agreement makes no difference to a self-employed filer — sourcing rules decide the answer instead.
How current is this?
The Connecticut and Missouri rules on this page were last checked against Connecticut Department of Revenue Services and Missouri 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.
- Connecticut Department of Revenue Services — individual income taxaccessed 2026-08-07
- Missouri Department of Revenue — individual income taxaccessed 2026-08-07