According to Chainalysis, addresses linked to illegal activities received $154 billion in 2025. This accounts for less than 1% of total transaction volume, yet AML systems at crypto exchanges continue to block accounts of legitimate users, including clients of Bitcoin mixers.
Together with the team from Mixer.Money, we explore how freezing mechanisms work and how to protect financial privacy without entering the "red zone" of compliance.
How AML Algorithms Work
Transaction verification on major platforms is handled by blockchain analytics providers like Chainalysis and Elliptic. They assign a risk score to each address and transaction, indicating the likelihood of being associated with illegal activity.
There is no universal threshold for freezing accounts; each exchange sets its own limits. When an algorithm detects suspicious activity, the platform freezes the account and files a Suspicious Activity Report (SAR). The subsequent decision follows a cascade model: first, automatic scoring, then manual analysis by a specialist, and if the risk level is high, a deep investigation with OSINT checks and document requests.
After sending the SAR to the regulator, the provider loses control over the process: attempting to return funds to the user without authorization from the authorities could be deemed illegal.
Common triggers for account blocking include:
- direct or indirect transactions with addresses on OFAC sanctions lists;
- receiving funds from darknet markets, scam projects, or addresses linked to ransomware;
- interacting with services that obscure transaction history—from cross-chain bridges to mixers.
“CoinJoin-transactions are easily identifiable on-chain. They record the mere fact of using a privacy tool. Meanwhile, the user’s ‘clean’ coins are mixed with potentially ‘dirty’ ones from unknown participants. AML services automatically increase the risk score of such assets,” note Mixer.Money.
A legitimate user may be unaware that they received ‘dirty’ coins, but their account can still be blocked due to automatic checks. This process takes seconds, while unlocking often drags on for weeks or even months.
Why Traditional Mixing Methods Are Becoming Risky
CoinJoin is an anonymization technology that combines transactions from multiple users into one. Participants send bitcoins to a common pool and receive equal amounts back to new addresses. The protocol is decentralized and does not require trust in an intermediary, but it leaves distinct traces on the blockchain.
In 2024, the U.S. Federal Prosecutor charged the founders of Samourai Wallet—one of the most popular CoinJoin wallets—with facilitating the laundering of $100 million. Shortly after, the company zkSNACK halted its CoinJoin coordinator in the Wasabi wallet.
These events intensified the “death spiral” of CoinJoin: the more exchanges block coins after mixing, the fewer law-abiding users utilize them. With fewer participants in the pool, it becomes easier to trace coin owners, leading to a higher concentration of ‘dirty’ funds.
“There’s little point in such mixing. Privacy advocates are forced to seek alternatives,” comment Mixer.Money.
Multi-step routes through bridges and swaps also do not help—platforms track cross-chain movements and link transactions by time and volume.
How Mixer.Money Addresses the Blocking Issue
To avoid freezing, users need coins that on-chain analytics deem legitimate. Mixer.Money tackles this through the bitcoin.mixer 2.0 algorithm—an approach where clients receive bitcoins not from other mixer users, but from major trading platforms.
In “Full Anonymity” mode, the service operates as follows:
- The user’s bitcoins go into a premixer and are split into random parts.
- The coins are sent to investors—independent traders who operate on major international exchanges. The platform utilizes funds from over 100 investors across various platforms worldwide.
- The user receives clean bitcoins from withdrawals of other exchanges to two new addresses.
For analytics services, such a transaction appears as a standard withdrawal from an exchange to a personal wallet. The fact of using a mixer is concealed, and the risk score remains minimal. Involvement of major trading platforms reduces the likelihood of receiving one’s own bitcoins or coins of dubious origin to nearly zero.
In addition to “Full Anonymity,” the service offers two additional modes:
- “Mixer”—basic anonymity for a 1% fee and up to two hours of waiting. Coins are mixed with funds from other clients. The fact of using the mixer may be noticeable upon deep analysis;
- “Exact Payment”—sending funds to a third party via the mixer. The seller receives payment “from the exchange” within six hours and cannot trace the source of the funds.
The service requires no registration and provides a guarantee letter with a PGP signature. A free test is available: when sending 0.001 BTC, the user receives it back without a fee.
Regulators Recognize the Right to Privacy
Despite tightening controls, the authorities' stance on privacy tools is changing. In 2022, OFAC imposed sanctions against Tornado Cash, and in October 2023, FinCEN proposed classifying cryptocurrency mixers as “money laundering centers.”
However, in March 2026, the U.S. Treasury submitted a report to Congress that for the first time at the federal level recognized the legitimacy of mixers for ensuring financial secrecy. The document explicitly states that law-abiding citizens use such tools to protect data about personal savings, confidential business payments, and charitable donations.
The Treasury did not recommend new restrictions—the agency continues to seek a balance between the risks of financing illegal activities and citizens' right to privacy.
“The report confirms: mixers are just one element of the financial system. Criminals use bridges, swaps, and OTC brokers. Banning mixers will not stop money laundering but will deprive ordinary users of basic privacy. It’s important that regulators are beginning to understand this,” summarize Mixer.Money.
This shift aligns with a broader trend. Venture capital fund a16z and Binance Research identified privacy as one of the key development areas for the crypto industry in 2026. In January, Senators Cynthia Lummis and Ron Wyden introduced a bill that exempts developers and providers of non-custodial services from needing to obtain money transfer operator licenses.
How to Avoid Getting Blocked
Compliance at exchanges today relies on automated monitoring. Several practical steps can help reduce the risk of freezing:
- check the wallet's risk score. Before sending funds to an exchange, ensure that the address is not marked as high-risk. AML services like BitOK, AMLOfficer, or BestChange can help;
- use anonymization tools that conceal the fact of mixing. CoinJoin transactions are easily identifiable by on-chain analytics and automatically increase the risk score. Services like Mixer.Money ensure that users receive coins with exchange history—this appears to analysts as a standard withdrawal from a trading platform;
- maintain financial hygiene after mixing. Do not combine UTXO from different sources in one transaction—this links anonymous coins to your identity. Avoid sending funds to addresses you used before mixing.
Automatic blocking on exchanges takes seconds, while unlocking can take weeks or months. Proactive protection is significantly cheaper than subsequent disputes with the compliance department.