The Czech Ministry of Finance has added prediction market platform Kalshi to its list of unauthorised internet gambling sites, which means internet service providers now have to block access to Kalshi.com in the country. The listing took effect on Sept. 30, following the same decision against rival Polymarket in July.
Czech law requires providers to block any website entered on the ministry’s blacklist, so Kalshi is now treated as an unauthorised gambling service rather than a financial trading platform. The ministry’s public register covers blocked websites, applications, and related payment information, and Czech reports say providers get 15 days from publication to put the restrictions in place. Vodafone had already blocked Kalshi on some fixed connections by Oct. 2.
Earlier in September, the ministry had signalled its intention to list Kalshi. According to Czech reporting, the domain was entered under Section 84a(2)(a) of the Gambling Act, which covers websites used to operate prohibited online gambling. Operators can raise objections before a listing becomes final, and the blocking requirements kick in after that.
The Institute for Gambling Regulation, or IPRH, welcomed the decision and argued that prediction markets should be regulated by how they actually work rather than how their products are labeled. Director Jan Řehola said users are still putting money on uncertain future events, whether a platform calls the product a contract, a probability, or a financial instrument instead of a bet.
Contracts on Kalshi are tied to real-world outcomes, including elections, sporting events, weather, interest rates, and entertainment. The company runs as a federally regulated designated contract market in the United States under the Commodity Futures Trading Commission, but that status gives it no permission to offer its products in countries that classify them as gambling.
Kalshi accounted for more than 80% of trading volume across the four major prediction platforms IPRH monitored in September, according to the institute. It put Kalshi’s September contract volume at around $59.2 billion, up roughly 48% from August, with about $238.8 billion traded on the platform between the start of 2026 and the end of September. Those numbers come from IPRH’s own market monitoring.
Polymarket went onto the same blacklist in July, and IPRH said at the time that the decision shouldn’t be treated as an isolated case and that regulators would need to look at other platforms offering comparable products. Kalshi’s listing shows Czech authorities applying that position to more than one operator.
Pressure on prediction markets outside the United States keeps building, with Kalshi and other platforms facing scrutiny in several European jurisdictions over whether event contracts count as financial products or gambling. That question gets sharpest when the contracts cover sports, elections, and other binary outcomes that bookmakers have traditionally offered.
Kalshi hasn’t publicly announced any legal challenge to the Czech decision. Ordinary access through Czech internet providers will be cut off progressively as they implement the order, while the Ministry of Finance continues to treat prediction markets offering unlicensed event contracts as online gambling under Czech law.