The Japanese crypto exchange Bitbank has warned customers of the risk of account suspension over transfers linked to Polymarket and other prediction market services. The company stated that using such platforms for financial gain may fall under local gambling legislation.

In its June 15 warning, Bitbank did not cite a specific regulatory order. The company explained the measures by its internal compliance controls and the need to comply with laws and guidelines.

What can lead to a ban

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

As an example, the exchange named Polymarket and other similar services with betting elements.

«If a deposit to or withdrawal from prediction market services, or services suspected of such a connection, is confirmed, we may apply account suspension measures», the warning reads.

The exchange urged customers to be more cautious in using external services so as not to become parties to illegal activity or disputes.

What will be disabled upon a ban

After an account is suspended, the user will lose access to:

• logging into the account;
• depositing and withdrawing crypto assets;
• withdrawing Japanese yen;
• trading crypto assets.

Bitbank separately stated that it will not be responsible for any losses customers may incur due to such measures.

«Even if a customer suffers damage as a result of account suspension measures, the company bears no responsibility whatsoever», Bitbank stated.

How this relates to Polymarket

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

According to Bloomberg, in May Polymarket was studying an entry into the Japanese market and expected to obtain approval from the authorities by 2030. The agency noted that strict local rules in the online betting sphere could complicate such plans.

Where Polymarket has faced bans

Bitbank's warning came amid tightening oversight of prediction markets in various jurisdictions. In early 2026, the Portuguese regulator demanded that Polymarket cease operations in the country after the volume of bets on the Portuguese presidential election exceeded €103 million.

In the spring, Spain temporarily blocked the prediction platform over the lack of a gambling license. Around the same time, Indonesia took similar measures against Polymarket.

Recall that in May, the platform's vice president of software development, Josh Stevens, denied rumors about the introduction of mandatory verification for all users.

Source: ForkLog