Is Kalshi legal in Missouri?

Attorney General Catherine L. Hanaway's office sent the letter to KalshiEX LLC through its registered agent in Delaware. It is dated September 16, 2026, carries Attorney General Hanaway's name on its letterhead and signature block, and is signed "/s/ Louis J. Capozzi, III" as Solicitor General (pp.1, 3). It opens with the office's charge: "Kalshi is an online sports wagering platform offering sports wagering to individuals located in the State of Missouri, despite not submitting to regulation by the Missouri Gaming Commission as required by Missouri law" (p.1). The office's release, posted September 18, says letters went to six companies: Polymarket, Kalshi, Crypto.com, Novig, Underdog and Robinhood.

The letter rests on three points, each the attorney general's reading of Missouri law.

A license. The release says voters approved sports wagering as Amendment 2 in 2024, with the licensed market launching on December 1, 2025. The letter cites the constitution (Mo. Const. art. III, § 39(g)1) for the voters' choice of a "well-regulated sports wagering industry", then says online platforms taking sports wagers from people in Missouri must be licensed by the Missouri Gaming Commission. Of that requirement it says, with no further cite, that it "is not optional and applies to Kalshi" (p.1).

Taxes and fees. The letter cites the constitution's 10% wagering tax on "the adjusted gross revenue" from in-state sports wagering, plus a license fee and a renewal fee every five years, each of which it says "could be as much as $500,000" (pp.1-2, citing art. III, § 39(g)6 and 10.a). That is a tax on the operator's sports wagering revenue, which the letter says Kalshi owes. It says Kalshi has kept "all of that money for itself" and that until it pays, "it will not be permitted to offer the use of its online sports wagering platform in Missouri" (p.2).

Age. Missouri bars sports wagering by anyone under 21 (11 C.S.R. § 45-20.360(1)(A)). The letter says Kalshi's Member Agreement lets anyone of the age of majority in their state, which it puts at 18 in Missouri, trade (p.2). Kalshi's Member Agreement has each individual member represent that they are "of the age of majority in Your state of residence" (p.2).

It gives Kalshi two options: stop, or get a Missouri Gaming Commission license, pay the state's taxes and fees, and stop offering sports wagering to anyone in Missouri under 21 (p.1). Its closing request, in full: "We ask that you confirm Kalshi’s compliance with Missouri law or its cessation of sports wagering activities in the State of Missouri within thirty days of the date of this letter" (p.3). Thirty days from September 16 is October 16, 2026.

The letter says "the State of Missouri will take legal action against Kalshi" if it does neither, and that Missouri "remains open to possible legislative reforms in the future" (p.3). Its demands are limited to sports wagering.

A cease-and-desist letter is a demand, not a court order. As of October 21, 2026, we found no attorney general release about Kalshi after the September 18 one, and we could not search court dockets, so we cannot say whether either side has sued. Kalshi's reply is not public. Spectrum News reported on October 4 that Kalshi was the first of the six companies to respond and that the attorney general's office described "ongoing discussions" with it.

The letter says nothing about withdrawals, deposits, accounts or open positions, and we found no court order in Missouri that does. Its demands are about offering sports wagering, not about funds already on the platform. As of October 21, 2026, we could not determine whether Kalshi has changed anything for Missouri users.

Kalshi's position, wherever states have challenged it, is that its contracts are derivatives traded on a CFTC-designated contract market, governed by federal commodities law rather than state gambling law. The letter answers that argument directly: it says Missouri "shares the same view as the majority of federal courts" that the Commodity Exchange Act does not preempt state law here and that the contracts are bets, not swaps, and it cites decisions from the Ninth and Sixth Circuits and five district courts (p.2). That is the attorney general's count. Its Sixth Circuit cite is an April 24, 2026 order of a motions panel, not that court's September 25 merits opinion.

The federal appeals courts that have ruled disagree. The Third Circuit ruled for Kalshi on April 6, 2026 (No. 25-1922). The Ninth Circuit ruled for Nevada on sports contracts on August 28 (No. 25-7516), and the Sixth Circuit ruled for Ohio and Tennessee on September 25 (Nos. 26-3196 and 26-5235). All three are preliminary-injunction rulings on federal commodities law.

Missouri's federal courts sit in the Eighth Circuit, where we found no ruling on Kalshi's contracts. Kalshi's appeal from an Iowa judge's September 8 refusal to block Iowa's regulators is there as KalshiEX v. Bird, No. 26-2874, and the court's schedule set Kalshi's brief for November 6, 2026. At the Supreme Court, Missouri's attorney general signed a brief by Ohio, 38 other states and the District of Columbia supporting New Jersey's petition against Kalshi (No. 26-299, p.24), where Kalshi's response is due November 9. Kalshi at the Supreme Court follows the petitions, is Kalshi gambling? sets out both sides, and every other state is on the Kalshi legal page.

Robinhood got its own. The attorney general sent Robinhood Derivatives, LLC a separate cease-and-desist letter the same day, built on the same three points and the same thirty-day request. It names Kalshi only in the captions of the court cases it cites. Coinbase and Webull are not among the six companies the release names, and we found no Missouri order aimed at any broker. Robinhood's legal status covers its side.

A state enforcement letter isn't a ruling on federal income tax, and the Missouri tax it cites is on an operator's revenue, not on your trades. How Realize rebuilds a Kalshi year's gains and losses from Kalshi's data is in how to file Kalshi taxes.