On this page
Banks and accounts
The account is the entry point. Every insured bank must keep Bank Secrecy Act compliance procedures, and examiners review them at each exam (12 U.S.C. 1818(s)). The guide lists the duties under banks.
Correspondent banking
A foreign bank reaches the dollar through a correspondent account: an account a U.S. bank opens for it to receive deposits, make payments, and handle other transactions on its behalf (31 CFR 1010.605). That is the gateway in the HSBC case file, and the route by which Danske's Estonian branch processed about $160 billion through U.S. banks. Section 312 of the PATRIOT Act requires enhanced due diligence on these accounts. The harder risk is what the correspondent cannot see: a respondent that lets other banks use its account brings in customers no U.S. bank has reviewed, and as banks withdrew, active correspondent relationships fell about 25 percent from 2011 to 2020, leaving more value on fewer links. The full article on correspondent banking covers nostro and vostro accounts, nesting, de-risking, the Section 319(b) subpoena and 981(k) seizure powers, the enforcement cases, and a worked investigation.
Full article
The Banking System: Correspondent BankingWires: Fedwire, CHIPS, and SWIFT
Large-value dollar transfers settle through two U.S. systems. The Federal Reserve's Fedwire Funds Service settles each payment individually in real time, and the payment is final once settled; in 2025 it settled about $1.148 quadrillion. CHIPS, run by The Clearing House, is the private counterpart: 43 direct participants, more than $2 trillion a day. SWIFT moves no money at all. It carries the payment instructions between more than 11,000 institutions. In 2016, attackers used Bangladesh Bank's SWIFT access to send 35 fraudulent orders against its account at the New York Fed. The full article on wires covers ISO 20022, cover payments, the Travel Rule, OFAC screening, BEC recalls, and the enforcement cases.
Full article
The Banking System: WiresACH and instant payments
Payroll direct deposits, benefit payments, and utility debits run on the ACH network, through which banks send each other batches of electronic credits and debits. Since July 2023 the Fed's FedNow Service has offered instant transfers around the clock. TD Bank chose not to automatically monitor domestic ACH transactions, and 92 percent of its transaction volume went unmonitored from 2018 to 2024.
Cards
A card payment involves the cardholder's bank (the issuer), the merchant, the merchant's bank (the acquirer), and a card network that carries authorization, clearing, and settlement between the two banks. Regulation II caps the interchange fee large debit card issuers can charge.
Money services businesses
Outside the banks, FinCEN's definition of a money services business covers money transmitters, check cashers, currency dealers and exchangers, and providers and sellers of prepaid access, among others (31 CFR 1010.100(ff)), and most must register with FinCEN. Hawala operators and crypto exchanges count too (see the guide on MSBs). At the Bank of New York in the 1990s, a vice president and her husband ran unlicensed transfer businesses that moved Russian money through the bank.