Live in Idaho, Work in Connecticut: Which State Taxes Your Paycheck?
Answer
Two returns, one credit. Connecticut has the first claim on wages earned inside the state and withholds accordingly. Idaho then taxes you as a resident on everything and gives credit for what Connecticut already took, capped at what Idaho would have charged on that same income.
Last verified
Without an agreement between Idaho and Connecticut, the overlap is handled after the fact rather than prevented. That is why the filing order matters: the Connecticut figure is an input to the Idaho return, so completing Idaho first means doing it twice.
A Idaho resident taxed by another state on the same income claims the credit for taxes paid to other states on Form 39NR. The credit is capped at the Idaho tax on that income, so it removes the double tax but never refunds the excess when the other state charges more.
What you file
- 1Nonresident return · ConnecticutForm CT-1040NR/PY
File the Connecticut nonresident return FIRST — you need the Connecticut tax figure before you can complete Idaho.
- 2Resident return · IdahoForm 39NR
File a Idaho resident return reporting all income, then claim the credit for tax paid to Connecticut. The credit is capped at what Idaho would have charged on that same income, so if Connecticut taxes it at a higher rate the difference is not refunded.
The two states, side by side
| Idaho | Connecticut | |
|---|---|---|
| Taxes wages | Yes — flat | Yes — graduated |
| Reciprocity partners | None | None |
| Convenience rule | No | Only against convenience-rule states |
| Nonresident return | Form 43 | Form CT-1040NR/PY |
| Credit for other-state tax | Form 39NR | Schedule 2 (Form CT-1040) |
| Nonresident safe harbour | None published | None published |
| Local income tax | No | No |
| Revenue department | Idaho State Tax Commission | 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 Idaho gives:Both states — credit offsets the double tax.
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.
- Remote worker: Idaho → ConnecticutHome state only
- 1099 contractor: Idaho → ConnecticutHome state, plus the client state if you work there
- Moved mid-year: Idaho → ConnecticutTwo part-year returns
Other Idaho pairs
Questions people actually ask
I live in Idaho and work in Connecticut. Which state takes the tax out of my paycheck?
Two returns, one credit. Connecticut has the first claim on wages earned inside the state and withholds accordingly. Idaho then taxes you as a resident on everything and gives credit for what Connecticut already took, capped at what Idaho would have charged on that same income.
Which state should my employer be withholding for?
Connecticut. The wages are sourced to Connecticut, so Connecticut withholding is correct and there is no Idaho withholding to set up.
Will I end up paying tax twice on the same income?
Not twice over, but you will pay the higher of the two rates. Idaho gives residents a credit for tax paid to Connecticut on the same income, claimed on Form 39NR. The credit is capped at the Idaho tax on that income, so if Connecticut taxes it more heavily the excess is not refunded by either state.
How current is this?
The Idaho and Connecticut rules on this page were last checked against Idaho State Tax Commission 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.
- Idaho State Tax Commission — individual income taxaccessed 2026-08-07
- Connecticut Department of Revenue Services — individual income taxaccessed 2026-08-07