If you're a freelancer, contractor, or single-member LLC in Missouri, you owe quarterly estimates to two agencies — IRS for federal, Missouri Department of Revenue for state. The top marginal rate is 4.7%. Penalties on under-paid estimates accrue independently per agency.
Missouri uses a progressive bracket system on top of federal tax. For single filers in 2026:
| Income (single filer) | Marginal rate |
|---|---|
| $0 – $1,313 | 0.00% |
| $1,313 – $2,626 | 2.00% |
| $2,626 – $3,939 | 2.50% |
| $3,939 – $5,252 | 3.00% |
| $5,252 – $6,565 | 3.50% |
| $6,565 – $7,878 | 4.00% |
| $7,878 – $9,191 | 4.50% |
| $9,191+ | 4.70% |
Federal estimated tax due dates (April 15, June 15, September 15, 2026, and January 15, 2027) apply to your Missouri state estimated payments as well — most states piggyback on the federal schedule. Pay Missouri taxes through the Missouri Department of Revenue's online portal: mytax.mo.gov. You can also mail Form MO-1040ES with a check.
Federal and state estimated tax safe harbors work in parallel for Missouri freelancers. Hit the federal safe harbor (90% of current-year federal tax OR 100% of prior-year federal tax — 110% if your prior-year AGI exceeded $150,000) and you avoid the IRS underpayment penalty on Form 2210.
For Missouri state estimated taxes, most filers can match the federal safe harbor approach by paying 100% of last year's Missouri tax in four equal quarterly installments. Missouri's underpayment penalty is calculated on the state's equivalent of Form 2210 — the DOR can assess interest plus a flat penalty on the under-paid amount.
Practical advice for Missouri self-employed taxpayers: pay both federal and state estimates on the same quarterly schedule (April 15, June 15, September 15, January 15). File your federal payment via IRS Direct Pay and your state payment via mytax.mo.gov. Keep records of every payment — both agencies can request proof if the safe-harbor math is challenged later.
Four Missouri-specific procedural items that trip up first-year filers:
Missouri has many narrow brackets but the top rate of 4.7% kicks in at relatively low income (~$9k). Effectively, most freelancers above subsistence-level pay the top rate. Kansas City and St. Louis residents owe additional 1% city earnings tax.
Five practical errors that consistently cost Missouri self-employed taxpayers: