What is Mutual Legal Assistance Treaty (MLAT)?

A Mutual Legal Assistance Treaty (MLAT) is a formal agreement between two or more countries that allows their legal systems to cooperate — specifically, to share evidence, compel witnesses, and assist with investigations across national borders.

What MLATs Do

When law enforcement in one country needs evidence that is located in another country — bank records, business documents, electronic communications — they generally cannot just subpoena a foreign institution directly. They use an MLAT request to ask the other country's government to compel that evidence through its own domestic legal process.

In practice, an MLAT request means:

• Country A's prosecutors contact Country B's justice ministry
• Country B reviews the request under its own laws
• If approved, Country B compels the evidence domestically and shares it
• The evidence can then be used in Country A's proceedings

Why It Matters for Privacy and Offshore Structures

MLATs are one reason why the assumption "my records are in another country, so foreign law enforcement can't reach them" is not reliable.

The United States has MLATs with most major economies and financial centers, including Switzerland, the UK, the EU, Cayman Islands, and dozens of others. Most offshore jurisdictions that are actually useful for banking have one with the US.

A serious criminal or civil investigation — tax fraud, money laundering, wire fraud — can use MLAT processes to obtain records from many jurisdictions that are often described as "private" banking locations.

The Practical Limits of MLATs

MLATs are not instant. They are slow — requests can take months or years to process. They also require dual criminality in some cases, meaning the conduct must be illegal in both countries for the request to be honored.

This is why MLATs are mainly relevant in serious investigations, not routine IRS audits or civil lawsuits. For commercial disputes and lower-stakes legal matters, the other party typically cannot use an MLAT — they need to pursue evidence through local civil courts.

What MLATs Don't Cover

MLATs are government-to-government instruments. They do not allow private parties (a former business partner, an ex-spouse, a creditor) to access foreign records. Private litigation across borders requires separate legal processes in each jurisdiction, which is significantly harder.

Key Takeaway

MLATs are the mechanism that allows serious cross-border investigations to reach records in offshore jurisdictions. They are a reason why "my assets are in [another country]" is not a reliable protection against determined legal pursuit — but they are not a tool available for routine or private disputes.