Cryptocurrency trading platform Bitfinex has recently distributed a letter to certain users, saying that they are required to disclose their tax information, which the exchange may share with the government, according to a statement from the exchange on Twitter May 17.

We have not sent this message to all users. We have deliberately targeted users that we believe have an obligation to self-disclose. If a user has _not_ received a message from us, she need _not_ self-certify anything to us at this time. — Bitfinex (@bitfinex) May 17, 2018

The exchange, which is registered in the British Virgin Islands (BVI), noted that under BVI law it is obliged to report specific information to the BVI government. According to the letter, Bitfinex “may then exchange” the information with tax authorities in concordance with the US Foreign Account Tax Compliance Act (FATCA) and the Organization for Economic Co-operation and Development Common Reporting Standard (CRS).

With the deadline to submit the information set for May 24, customers, according to the notice, must complete self-certification forms depending on whether they’re individuals or entities, and whether they’re residents or citizens of the US:

“If you are a US person (i.e. a US resident, a US citizen, or an entity organized in the United States), or an entity with at least one 25%+ owner who is a US person, please complete the appropriate FATCA form. Otherwise complete the appropriate CRS form.”

The message was confirmed by the Bitfinex Twitter account after the exchange’s new policy was brought to light by cryptocurrency commentator Whalepool:

“We have not sent this message to all users. We have deliberately targeted users that we believe have an obligation to self-disclose. If a user has _not_ received a message from us, she need _not_ self-certify anything to us at this time.”

Bitfinex was founded in 2012 and is headquartered in Hong Kong. At a market capitalization of $686 mln, it is the fourth-largest cryptocurrency exchange globally, trading 77 different digital assets.

Last month, Bitfinex fell under the “Virtual Markets Integrity Initiative”, an “inquiry into the policies and practices” of crypto trading platforms launched by then-New York Attorney General Eric T. Schneiderman. As part of the program, the exchange was sent a letter, asking them to provide information on operations, internal controls, and other key issues in order to protect cryptocurrency investors and users.