1099 Contractor in Washington with a Missouri Client: Where Do You File?
Answer
The client's address is not the test. Washington has no personal income tax, so nothing is owed at home; Missouri taxes nonresidents on income from services performed within Missouri, so if you never travel there to work, there is nothing to file. Days on site change that.
Last verified
The most common contractor worry — that invoicing an out-of-state client creates a filing obligation there — is usually unfounded. What creates the obligation is physical presence, and Washington residents have no home-state return in any case.
Missouri publishes no de minimis day count or dollar floor for nonresidents. Any Missouri-source wage income above the state's general filing threshold requires a nonresident return, and that threshold is reset each year — check the current figure on the Missouri Department of Revenue nonresident instructions before filing.
What you file
- 1Nonresident return · MissouriForm MO-1040 with Form MO-NRI
File a Missouri nonresident return only for income from services you physically performed in Missouri. Washington does not tax wage or self-employment income.
The two states, side by side
| Washington | Missouri | |
|---|---|---|
| Taxes wages | No | Yes — graduated |
| Reciprocity partners | None | None |
| Convenience rule | No | No |
| Nonresident return | Not applicable | Form MO-1040 with Form MO-NRI |
| Credit for other-state tax | No income tax | Form MO-CR |
| Nonresident safe harbour | Not applicable | None published |
| Local income tax | No | Yes |
| Revenue department | Washington State Department of Revenue | Missouri Department of Revenue |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in Missouri and working in Washington gives:Home state only — estimated payments.
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 → MissouriWork state only
- Remote worker: Washington → MissouriNo state income tax on your wages
- Moved mid-year: Washington → MissouriOne part-year return — the state you moved to
Other Washington pairs
Questions people actually ask
I live in Washington and my client is in Missouri. Do I have to file a Missouri tax return?
The client's address is not the test. Washington has no personal income tax, so nothing is owed at home; Missouri taxes nonresidents on income from services performed within Missouri, so if you never travel there to work, there is nothing to file. Days on site change that.
Do reciprocity agreements help a 1099 contractor?
No. Every state reciprocity agreement in the country is an arrangement about wage withholding between two revenue departments, and a 1099 has no withholding to switch off. Whether Washington and Missouri hold an agreement makes no difference to a self-employed filer — sourcing rules decide the answer instead.
How current is this?
The Washington and Missouri rules on this page were last checked against Washington State Department of Revenue and Missouri 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
- Missouri Department of Revenue — individual income taxaccessed 2026-08-07