Moved from Montana to Oklahoma Mid-Year: Which State Tax Returns Do You File?
Answer
Two returns, split at the move date. Montana and Oklahoma 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
A mid-year move splits the tax year in two, and each state taxes its own half. That is a residency question, so the machinery that governs commuters — reciprocity agreements, convenience rules, nonresident withholding — is beside the point here.
What you file
- 1Part-year return · MontanaForm 2 with the nonresident/part-year schedule
File a Montana part-year return covering the months you lived in Montana. A part-year resident of Montana reports the income received while a Montana resident, plus any Montana-source income received during the rest of the year, and prorates the deductions and credits to the residency period.
- 2Part-year return · OklahomaForm 511-NR
File a Oklahoma part-year return covering the months you lived in Oklahoma. A part-year resident of Oklahoma reports the income received while a Oklahoma resident, plus any Oklahoma-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
| Montana | Oklahoma | |
|---|---|---|
| Taxes wages | Yes — graduated | Yes — graduated |
| Reciprocity partners | 1 (Form MW-4) | None |
| Convenience rule | No | No |
| Nonresident return | Form 2 with the nonresident/part-year schedule | Form 511-NR |
| Part-year return | Form 2 with the nonresident/part-year schedule | Form 511-NR |
| Credit for other-state tax | Form 2 (credit for income tax paid to another state) | Form 511-TX |
| Nonresident safe harbour | None published | None published |
| Local income tax | No | No |
| Revenue department | Montana Department of Revenue | Oklahoma Tax Commission |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in Oklahoma and working in Montana 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: Montana → OklahomaBoth states — credit offsets the double tax
- Remote worker: Montana → OklahomaHome state only
- 1099 contractor: Montana → OklahomaHome state, plus the client state if you work there
Other Montana pairs
Questions people actually ask
I moved from Montana to Oklahoma mid-year. Do I have to file in both states?
Two returns, split at the move date. Montana and Oklahoma 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 Montana and Oklahoma?
By when you received it, measured against the date your domicile actually changed. Income received while you were a Montana resident belongs on the Montana return and income received afterwards on the Oklahoma 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 Montana and Oklahoma rules on this page were last checked against Montana Department of Revenue and Oklahoma Tax Commission 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.
- Montana Department of Revenue — individual income taxaccessed 2026-08-07
- Oklahoma Tax Commission — individual income taxaccessed 2026-08-07