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Moved from Mississippi to Idaho Mid-Year: Which State Tax Returns Do You File?

Two part-year returnsBoth states claim the income

Answer

Two returns, split at the move date. Mississippi and Idaho 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

  1. 1Part-year return · MississippiForm 80-205

    File a Mississippi part-year return covering the months you lived in Mississippi. A part-year resident of Mississippi reports the income received while a Mississippi resident, plus any Mississippi-source income received during the rest of the year, and prorates the deductions and credits to the residency period.

  2. 2Part-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.

The two states, side by side

 MississippiIdaho
Taxes wagesYes — flatYes — flat
Reciprocity partnersNoneNone
Convenience ruleNoNo
Nonresident returnForm 80-205Form 43
Part-year returnForm 80-205Form 43 (part-year resident)
Credit for other-state taxForm 80-160Form 39NR
Nonresident safe harbourNone publishedNone published
Local income taxNoNo
Revenue departmentMississippi Department of RevenueIdaho State Tax Commission
Last verified

The other direction

Reversing the commute does not always reverse the answer. Living in Idaho and working in Mississippi gives:Two part-year returns.

Idaho to Mississippi →

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.

Other Mississippi pairs

Questions people actually ask

I moved from Mississippi to Idaho mid-year. Do I have to file in both states?

Two returns, split at the move date. Mississippi and Idaho 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 Mississippi and Idaho?

By when you received it, measured against the date your domicile actually changed. Income received while you were a Mississippi resident belongs on the Mississippi return and income received afterwards on the Idaho 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 Mississippi and Idaho rules on this page were last checked against Mississippi Department of Revenue and Idaho State 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.