Treasury Severs MEXC From US Financial System Over $16B in Illicit Flows

The US Treasury Department ordered crypto exchange MEXC Global cut off from the American financial system on Friday, citing at least $16 billion in transactions linked to illicit finance. The Financial Crimes Enforcement Network (FinCEN) issued the order, which bars US financial institutions from processing any funds transfers to or from the exchange.

The figures span five years. Treasury found MEXC processed at least $16 billion in illicit-finance-linked transactions between May 2021 and May 2026 — roughly $3.2 billion per year. Nearly $1.5 billion of that total connected to Russian sanctions evasion, including $232 million in direct dealings with entities sanctioned by the US, European Union and United Kingdom.

What did FinCEN actually find?

The findings paint a picture of an exchange that kept processing sanctioned counterparties long after the rules were clear. Treasury said MEXC continued transactions involving Garantex, the Russian exchange sanctioned in April 2022, and its successor Grinex as recently as June 2026. That is more than four years after the original designation.

The Russian file carries specific numbers:

• At least $26 million in transactions benefiting the sanctioned A7 network
• Nearly $200 million connected to A7A5, a stablecoin Treasury says the network uses for sanctions evasion

Iranian exposure ran wider, though at lower intensity. Between May 2021 and May 2026, MEXC sent or received approximately $1 billion in direct transfers involving more than 40 Iranian crypto exchanges, some of them themselves under international sanctions. Treasury also identified roughly $22 million in transactions benefiting Iran's central bank and the Islamic Revolutionary Guard Corps, including its Qods Force.

Iranian activity made up a substantial share of the identified flows, though Treasury did not publish a precise breakdown beyond the $1 billion and $22 million figures. Takeaway: the enforcement case rests on years of documented transfers, not a single incident.

Why did MEXC's controls fail?

FinCEN's finding here is the most consequential part of the order. The exchange had written policies prohibiting activity involving sanctioned jurisdictions. The regulator concluded those policies did not work in practice, because deficiencies in anti-money-laundering controls allowed prohibited transactions to continue.

That distinction matters operationally. A compliance failure of this kind signals to other exchanges that documented policy is not a defense when controls do not stop sanctioned flows. Institutions banking crypto platforms will read the order as a reason to re-examine correspondent relationships with exchanges showing similar control gaps.

What legal authority and campaign does this sit under?

The order draws on Section 9714(a) of the Combating Russian Money Laundering Act. It takes effect 30 days after publication in the Federal Register. Financial institutions that violate the restrictions face civil or criminal penalties.

The action also forms part of Operation Economic Outcast, a Treasury campaign launched in August targeting financial networks supporting Iran and its sanctions-evasion activity. MEXC is therefore one node in a broader enforcement push, not an isolated case; further designations against related networks remain a live possibility.

How large is the business being cut off?

MEXC is not a marginal venue. As of September, according to Treasury figures, it processed more than $1 billion in daily trading volume — roughly $365 billion annualized at that pace — and held approximately $5 billion in reserves. The exchange offered access to more than 3,000 cryptocurrencies and tokenized assets.

Being severed from US financial institutions means MEXC cannot rely on American banks or payment rails for dollar settlement, a constraint that typically forces offshore exchanges deeper into stablecoin-based settlement channels. Whether those channels themselves attract the next enforcement action is an open question Treasury has not yet answered.

The clock now runs 30 days from Federal Register publication; after that, any US institution touching MEXC transfers does so at legal risk.