Moved from Idaho to Arizona Mid-Year: Which State Tax Returns Do You File?
Answer
Two returns, split at the move date. Idaho and Arizona both tax residents, so each takes the portion of the year you were one. This is a residency question rather than a sourcing question — reciprocity agreements and convenience rules have nothing to do with it.
Last verified
Part-year returns are designed so that neither state taxes the whole year. The risk is not double taxation by default; it is misassigning income received near the move date, and losing the proration on deductions and credits.
What you file
- 1Part-year return · IdahoForm 43 (part-year resident)
File a Idaho part-year return covering the months you lived in Idaho. A part-year resident of Idaho reports the income received while a Idaho resident, plus any Idaho-source income received during the rest of the year, and prorates the deductions and credits to the residency period.
- 2Part-year return · ArizonaForm 140PY
File a Arizona part-year return covering the months you lived in Arizona. A part-year resident of Arizona reports the income received while a Arizona resident, plus any Arizona-source income received during the rest of the year, and prorates the deductions and credits to the residency period.
The two states, side by side
| Idaho | Arizona | |
|---|---|---|
| Taxes wages | Yes — flat | Yes — graduated |
| Reciprocity partners | None | None |
| Convenience rule | No | No |
| Nonresident return | Form 43 | Form 140NR |
| Part-year return | Form 43 (part-year resident) | Form 140PY |
| Credit for other-state tax | Form 39NR | Form 309 |
| Nonresident safe harbour | None published | None published |
| Local income tax | No | No |
| Revenue department | Idaho State Tax Commission | Arizona Department of Revenue |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in Arizona and working in Idaho gives:Two part-year returns.
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: Idaho → ArizonaBoth states — credit offsets the double tax
- Remote worker: Idaho → ArizonaHome state only
- 1099 contractor: Idaho → ArizonaHome state, plus the client state if you work there
Other Idaho pairs
Questions people actually ask
I moved from Idaho to Arizona mid-year. Do I have to file in both states?
Two returns, split at the move date. Idaho and Arizona both tax residents, so each takes the portion of the year you were one. This is a residency question rather than a sourcing question — reciprocity agreements and convenience rules have nothing to do with it.
How do I split my income between Idaho and Arizona?
By when you received it, measured against the date your domicile actually changed. Income received while you were a Idaho resident belongs on the Idaho return and income received afterwards on the Arizona return, with each state prorating your deductions, exemptions and credits to its own part of the year. Keep evidence of the move date — a lease, a closing statement, a licence issue date.
How current is this?
The Idaho and Arizona rules on this page were last checked against Idaho State Tax Commission and Arizona 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.
- Idaho State Tax Commission — individual income taxaccessed 2026-08-07
- Arizona Department of Revenue — individual income taxaccessed 2026-08-07