The Japanese cryptocurrency exchange Bitbank has warned clients about the risk of account suspensions due to transfers associated with Polymarket and other prediction market services. The company stated that using such platforms for financial gain may fall under local gambling laws.

In a warning issued on June 15, Bitbank did not reference any specific regulatory directive. The company explained that the measures are part of internal compliance controls and the necessity to adhere to laws and guidelines.

Reasons for Potential Suspension

According to Bitbank, prediction markets allow users to trade on the outcomes of future events, including elections and sports results. While such services may operate outside of Japan, accessing them from within the country for financial gain poses legal risks.

As an example, the exchange mentioned Polymarket and other similar services that incorporate betting elements.

“If deposits or withdrawals are confirmed from prediction market services or services suspected of such connections, we may take measures to suspend the account,” the warning stated.

The exchange urged clients to exercise caution when using external services to avoid becoming involved in illegal activities or disputes.

What Access Will Be Restricted Upon Suspension

After an account suspension, the user will lose access to:

  • account login;
  • depositing and withdrawing crypto assets;
  • withdrawing Japanese yen;
  • trading crypto assets.

Bitbank specifically noted that it will not be liable for any potential losses incurred by clients due to these measures.

“Even if a client suffers losses as a result of account suspension measures, the company bears no responsibility,” Bitbank stated.

Connection to Polymarket

In the documentation for Polymarket, Japan is listed as a jurisdiction with restricted access to the platform's user interface. This restriction applies to the website but not to the application programming interface. The service also noted that geographic restrictions are related to sanctions compliance, local financial regulations, prediction market and gambling laws, as well as anti-money laundering and customer identification requirements.

According to Bloomberg, Polymarket was exploring entry into the Japanese market in May and aimed to obtain regulatory approval by 2030. The agency noted that strict local rules regarding online betting could complicate such plans.

Where Polymarket Faced Restrictions

Bitbank's warning comes amid increased scrutiny of prediction markets across various jurisdictions. In early 2026, the Portuguese regulator demanded that Polymarket cease operations in the country after betting volume on the Portuguese presidential elections exceeded €103 million.

In the spring, Spain temporarily blocked the prediction platform due to a lack of gambling licenses. Similar measures against Polymarket were also taken by Indonesia at that time.

It is worth noting that in May, the platform's Vice President of Software Development, Josh Stevens, denied rumors of mandatory verification for all users.