The Black Market Peso Exchange (BMPE) is a trade-based money laundering technique commonly used by narcotics traffickers based in Colombia and Mexico. The central feature is the use of a money trader to ensure that the revenue from drug sales in the U.S. doesn't actually cross any borders. Instead, those dollars are used to purchase any number of legitimate commodities from unsuspecting businesses on behalf of legitimate South American businesspersons, whose legitimate imports are used to obtain pesos for the drug cartels12. The BMPE involves six distinct steps:
Obtaining criminal proceeds: The drug cartels sell drugs for dollars in the U.S.
Involvement of intermediary services: The drug cartels sell the dollars to black market peso exchangers in Colombia at a discounted rate.
Identification of complicit companies: The black market peso exchangers identify exporting companies in the U.S. and importing companies in South America that are willing to participate in the scheme.
Placement of funds: The black market peso exchangers deposit the dollars into U.S. bank accounts or use money service businesses or other methods to transfer the funds.
Layering of funds: The black market peso exchangers use the funds to purchase monetary instruments such as checks, money orders, or wire transfers, or to pay for the goods ordered by the South American importers.
Integration of funds: The South American importers receive the goods or the monetary instruments and use them to pay for their imports or to sell them for pesos in the local market.
Reference:
1: Black Market Peso Exchange in Money Laundering - Financial Crime Academy
2: Overview - FinCEN.gov