Correspondent banking abuse hides a party behind a bank that knows only its own customer. Securities custody has the same structural gap, one market up: a custodian holding shares or bonds for a foreign intermediary generally knows the intermediary, and knows nothing about who the intermediary is holding them for.
How it works
Securities held for many clients of the same intermediary are commonly pooled into one omnibus account at the custodian, recorded in the intermediary’s own name. That pooling is ordinary market infrastructure — it is what lets custody and settlement scale — and the overwhelming majority of omnibus accounts are entirely routine.
The evasion use exploits exactly what makes it efficient. A restricted party’s beneficial interest in a security sits inside the intermediary’s account rather than in an account of its own, so a US custodian screening the names on its own books screens the intermediary, not the restricted party. ISSA’s compliance principles for the industry put the obligation the other way round: custodians should screen “the underlying Clients holding Segregated Accounts with the Account Holder and (if different) the Ultimate Assets Beneficial Owner(s)”2 against the sanctions lists — not only the account holder of record.
Moving the record, not the interest
The Clearstream case is the clearest illustration on this site of a second variant: changing which account holds a position without changing who benefits from it. OFAC’s notice describes Clearstream moving securities in which the Central Bank of Iran held a beneficial interest to a different account, by “free of payment” transfer. The record owner changed. The beneficial owner did not. OFAC’s finding states it directly: “due to the omnibus nature of Clearstream’s account in New York, the CBI’s beneficial ownership interest in the 26 securities was not transparent to the U.S. financial institution”4 .
When disclosure never happens at all
A simpler variant needs no transfer. The EFG case on this site describes trades executed and held in the bank’s own name at US custodians for years, for clients resident in Cuba and for a person later designated under the Kingpin Act, without the US custodians being told. The gap was not a single event; it was the ordinary operation of the account, left unexamined.
How it is caught
Custodian-level UBO screening. Screening the account holder is necessary and not sufficient. ISSA’s principles ask custodians to reach the underlying client and ultimate beneficial owner where an omnibus or segregated arrangement is in use1 .
Periodic reassessment. An omnibus relationship approved once is not approved forever. Custodians “have the right to assess their Account Holders periodically to determine the appropriateness of maintaining Client Omnibus Accounts”3 , and a relationship whose risk profile has changed is a candidate for that reassessment.
Tracing transfers by beneficial interest, not by record owner. A change in which account holds a position is not informative on its own. What matters is whether the party who benefits from the position changed too.
Post-designation notification. Once a client or a position is designated, the obligation shifts from screening to disclosure: telling every custodian and counterparty down the chain what is now blocked, promptly and completely, as the EFG case shows can otherwise be missed by simple omission for years.
What this does and does not require
It does not require an offshore secrecy jurisdiction or a shell company. Every institution in the Clearstream and EFG cases is a regulated bank or a regulated central securities depository operating in ordinary financial centres. The opacity comes from the custody structure itself, not from where any party is located.
It also does not work against a party already named on a sanctions list at the point of transfer: OFAC’s finding against Clearstream turns on Clearstream having “reason to know” the Central Bank of Iran retained the beneficial interest, not on a screening system failing to match a name. The gap this technique exploits is disclosure, not name-matching.