1099 Contractor in Kansas with a Connecticut Client: Where Do You File?
Answer
Two possible returns, one certainty. The certainty is Kansas, which taxes residents on all self-employment income and expects quarterly estimated payments. The possibility is Connecticut, which taxes nonresidents on services actually performed inside the state — invoices sent there do not count.
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 Connecticut is measured in days on the ground rather than in invoices sent.
Connecticut publishes no de minimis day count or dollar floor for nonresidents. Any Connecticut-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 Connecticut Department of Revenue Services nonresident instructions before filing.
What you file
- 1Quarterly estimated payments · Kansas
Make quarterly estimated payments to Kansas Department of Revenue on your full self-employment income — nothing is withheld from a 1099.
- 2Nonresident return · ConnecticutForm CT-1040NR/PY
File a Connecticut nonresident return only if you performed services inside Connecticut. Connecticut publishes no de minimis day count or dollar floor for nonresidents. Any Connecticut-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 Connecticut Department of Revenue Services nonresident instructions before filing.
- 3Resident return · KansasForm K-40 (credit for taxes paid to other states)
File the Kansas resident return last and claim the credit for any tax paid to Connecticut.
The two states, side by side
| Kansas | Connecticut | |
|---|---|---|
| Taxes wages | Yes — graduated | Yes — graduated |
| Reciprocity partners | None | None |
| Convenience rule | No | Only against convenience-rule states |
| Nonresident return | Form K-40 with Schedule S Part B | Form CT-1040NR/PY |
| Credit for other-state tax | Form K-40 (credit for taxes paid to other states) | Schedule 2 (Form CT-1040) |
| Nonresident safe harbour | None published | None published |
| Local income tax | No | No |
| Revenue department | Kansas Department of Revenue | Connecticut Department of Revenue Services |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in Connecticut and working in Kansas 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: Kansas → ConnecticutBoth states — credit offsets the double tax
- Remote worker: Kansas → ConnecticutHome state only
- Moved mid-year: Kansas → ConnecticutTwo part-year returns
Other Kansas pairs
Questions people actually ask
I live in Kansas and my client is in Connecticut. Do I have to file a Connecticut tax return?
Two possible returns, one certainty. The certainty is Kansas, which taxes residents on all self-employment income and expects quarterly estimated payments. The possibility is Connecticut, 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 Kansas and Connecticut hold an agreement makes no difference to a self-employed filer — sourcing rules decide the answer instead.
How current is this?
The Kansas and Connecticut rules on this page were last checked against Kansas Department of Revenue and Connecticut Department of Revenue Services 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.
- Kansas Department of Revenue — individual income taxaccessed 2026-08-07
- Connecticut Department of Revenue Services — individual income taxaccessed 2026-08-07