*ditto* to Dixie ...
It is a "risk based" approach. If you don't search SDB customers, you must state why. Most banks do not offer SDB to non-customers, therefore they are protected with OFAC & 314(a) Searches.
The FFIEC Manual states:
Based on the bank’s OFAC risk profile for each area and available technology, the bank should establish policies, procedures, and processes for reviewing transactions and transaction parties (e.g., issuing bank, payee, endorser, or jurisdiction). Currently, OFAC provides guidance on transactions parties on checks. The guidance states if a bank knows or has reason to know that a transaction party on a check is an OFAC target, the bank’s processing of the transaction would expose the bank to liability, especially personally handled transactions in a high-risk area. For example, if a bank knows or has a reason to know that a check transaction involves an OFAC-prohibited party or country, OFAC would expect timely identification and appropriate action.
I would also review pg 142.
My opinions are my own, and not that of my employer.