Moved from Washington to Illinois Mid-Year: Which State Tax Returns Do You File?
Answer
One return, filed in Illinois. Washington levies no personal income tax, so nothing is due for the part of the year you lived there. A Illinois part-year return covers the income you received after the move, with deductions and credits prorated to that period.
Last verified
Coming from a state with no income tax means arriving with no Illinois withholding history and no prior-year liability to base estimates on. The first Illinois return is where that catches up, so the withholding start date matters.
What you file
- 1Part-year return · IllinoisForm IL-1040 with Schedule NR
File a Illinois part-year return covering the months you lived in Illinois. Washington has no wage income tax, so there is nothing to file for the earlier part of the year.
The two states, side by side
| Washington | Illinois | |
|---|---|---|
| Taxes wages | No | Yes — flat |
| Reciprocity partners | None | 4 (Form IL-W-5-NR) |
| Convenience rule | No | No |
| Nonresident return | Not applicable | Form IL-1040 with Schedule NR |
| Part-year return | Not applicable | Form IL-1040 with Schedule NR |
| Credit for other-state tax | No income tax | Schedule CR |
| Nonresident safe harbour | Not applicable | 30 days |
| Local income tax | No | No |
| Revenue department | Washington State Department of Revenue | Illinois Department of Revenue |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in Illinois and working in Washington gives:One part-year return — the state you left.
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: Washington → IllinoisWork state only
- Remote worker: Washington → IllinoisNo state income tax on your wages
- 1099 contractor: Washington → IllinoisClient state only, if you work there
Other Washington pairs
Questions people actually ask
I moved from Washington to Illinois mid-year. Do I have to file in both states?
One return, filed in Illinois. Washington levies no personal income tax, so nothing is due for the part of the year you lived there. A Illinois part-year return covers the income you received after the move, with deductions and credits prorated to that period.
How do I split my income between Washington and Illinois?
By when you received it, measured against the date your domicile actually changed. Income received while you were a Washington resident belongs on the Washington return and income received afterwards on the Illinois return. Keep evidence of the move date — a lease, a closing statement, a licence issue date.
How current is this?
The Washington and Illinois rules on this page were last checked against Washington State Department of Revenue and Illinois 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.
- Washington State Department of Revenue — individual income taxaccessed 2026-08-07
- Illinois Department of Revenue — individual income taxaccessed 2026-08-07