Before you start

An SSN or ITIN
Form W-4 with your employer for federal withholding and Missouri Form MO W-4 for state withholding
Certainty about whether your home and your workplace are inside the City of St. Louis
Records of foreign income and foreign financial accounts

Step-by-step

1
Complete the W-4 and the MO W-4 on day one
Missouri withholding derives from its own form rather than the federal one. If your employer is inside the city, they will also withhold the 1% earnings tax automatically; if you live in the city and work outside it, nobody withholds it and you owe it directly.
Via employerWho: YouFirst week of employment
2
Establish which side of the city line your home and your office are on
The City of St. Louis is an independent city with hard boundaries that do not follow the metro's shape. Clayton, University City, Maplewood and Richmond Heights are all in St. Louis County and levy no earnings tax; the Central West End, Soulard and Downtown are all in the city and do. Confirm both addresses before you sign anything.
OnlineWho: YouBefore signing a lease
3
File Form E-1 by 15 April
The individual earnings tax return covers residents on their total earnings and non-residents on the portion earned inside the city. It is separate from the Missouri return and separate from the federal one.
OnlineWho: YouBy 15 April annually
4
If you are a non-resident with days worked outside, file Form E-1R
A non-resident whose employer withheld the full 1% but who worked whole days outside the city claims the difference back on Form E-1R, with the days verified by the employer. It is a refund request, not an automatic adjustment, and it has its own deadline.
OnlineWho: YouBy 15 April
5
Claim the Missouri capital gains deduction if it applies
For tax years from 2025, individuals may deduct 100% of capital gains reported for federal purposes when computing Missouri adjusted gross income — both short and long term. It is claimed on the Missouri return, not automatically applied.
OnlineWho: You
6
File an FBAR if foreign accounts exceed $10,000
Aggregate foreign account balances over $10,000 at any point in the year trigger a FinCEN filing, separate from every one of your income tax returns.
OnlineWho: You

Documents you’ll need

Form W-2 from each employer, showing state and local withholding
Form 1099s for freelance, interest and investment income
Your home and work addresses, checked against the city boundary
Employer verification of days worked outside the city, for a Form E-1R claim
Foreign account statements for FBAR reporting

Things most newcomers don’t know

The earnings tax boundary is the city limit, and it is not where newcomers think it is.

The independent city's border cuts through what looks like continuous urban fabric. Clayton — the region's second downtown and the county seat — is outside it; the Central West End, half a mile away, is inside. Moving a lease or an office across that line changes your take-home by a full percent of gross, and nothing about the neighbourhoods signals it.

Source: City of St. Louis Collector of Revenue

The refund for days worked outside the city is yours to claim, not payroll's to adjust.

Employers inside the city withhold the full 1% regardless of where the work was actually done. A non-resident who travels, or works from home outside the city, recovers the difference by filing Form E-1R with employer verification of the whole days worked elsewhere. Nobody prompts you, and unclaimed refunds simply lapse.

Source: City of St. Louis Collector of Revenue

Missouri is the first state to fully exempt individual capital gains.

Legislation signed in July 2025 lets individuals deduct 100% of federally reported capital gains from Missouri adjusted gross income from tax year 2025. No other state does this. For anyone holding equity compensation or selling property, it is a material and genuinely unusual advantage — and it has to be claimed on the return.

Source: Missouri Department of Revenue — 2025 legislative changes

Missouri taxes what you own as well as what you earn.

Personal property tax is charged annually on vehicles, boats and trailers at 33⅓% of value as of 1 January, and the paid receipt is required to renew your plates. Arrivals from states with no personal property tax do not budget for it, and a missed bill turns into an unregisterable car rather than just a late fee.

Source: City of St. Louis Assessor

Common mistakes to avoid

Signing a city lease without pricing the 1% earnings tax into the rent comparison.
Living in the city and working outside it, and assuming somebody is withholding the earnings tax — nobody is.
Not filing Form E-1R for days genuinely worked outside the city.
Missing the Missouri capital gains deduction because it is claimed rather than automatic.
Forgetting the annual personal property tax and finding the plates cannot be renewed.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.