FinCEN drops proposed crypto mixing rule

The U.S. Treasury’s Financial Crimes Enforcement Network (FinCEN) withdrew its proposed rule on international convertible virtual currency (CVC) mixing on October 6, ending a plan to require covered financial institutions to report certain mixing transactions. In its Federal Register withdrawal notice, FinCEN said commenters warned that the proposal’s expansive definition could chill legitimate activity and impose a large reporting burden. The agency said it still considers mixers a tool used by illicit actors to hinder law enforcement investigations.

The withdrawal concerns a proposed rule published in October 2023 under Section 311 of the USA PATRIOT Act. FinCEN had found that international CVC mixing was a class of transactions of primary money-laundering concern and proposed applying “special measure one”: additional recordkeeping and reporting requirements for covered financial institutions. The proposal never took effect. The Block reported on the withdrawal that ending the proposal does not change institutions’ existing obligations.

What activity would the proposed rule have covered?

FinCEN defined CVC mixing as facilitating transactions in a way that obscures the source, destination or amount, regardless of the protocol or service. The definition included pooling funds from multiple people or wallets, using code to structure a transaction, splitting funds across independent transactions, using single-use wallets, exchanging between digital assets and introducing user-requested delays.

That scope reached beyond a particular mixer design. A “CVC mixer” could have been any person, group, service, code, tool or function facilitating mixing. The proposed rule applied to transactions within or involving a jurisdiction outside the United States. It would have required covered institutions to file reports when they knew, suspected or had reason to suspect that a transaction involved CVC mixing.

What information would institutions have had to report?

Reports would have included details such as the amount and type of CVC, the mixer used, customer-associated wallet addresses, transaction hashes, dates, IP addresses and a narrative describing the activity. Institutions would also have kept records identifying customers associated with covered transactions, including names, dates of birth, addresses, email addresses or unique identifying numbers.

The proposal’s reporting path ran through regulated financial institutions, rather than imposing a direct filing duty on every mixer user. Its breadth still mattered to privacy-preserving activity on public blockchains: pooling, transaction splitting and single-use addresses can make links between a sender and recipient harder to follow, and the proposed definition expressly included those methods. A July 2025 report by the President’s Working Group on Digital Asset Markets, cited in the notice, recognized that lawful users may use mixers for financial privacy and recommended that Treasury consider next steps on the proposal.

Does the withdrawal end FinCEN’s scrutiny of mixers?

No. FinCEN said it will continue monitoring CVC mixer activity for signs of money laundering, terrorist financing or other illicit finance, and may take future steps. The agency withdrew the specific Section 311 finding and proposed reporting measure; it did not say that illicit use had stopped. Its stated decision was shaped by the risk that the proposal’s broad coverage could burden financial institutions and chill legitimate activity while the agency continues to assess mixer-related risks.

Sources and documents

• Federal Register withdrawal notice — federalregister.gov
• reported on the withdrawal — theblock.co