Offshore triangular trade, where goods never enter the border and the domestic firm earns the spread, is the compliance base under SNSUC's crude transfers. Article 14 of the FX guidance draws a hard line: each offshore triangular deal should, in principle, settle at one bank and in one currency. A cross-bank or cross-currency deal must be verified as genuine first, and the reporting note must state "special offshore triangular trade," with the foreign exchange bureau notified within five business days of handling.

That line forces clean books. The seven transfer grades, ESPO, Dubai, Oman, Urals, Basrah Light, Bonny Light and Lula, must run purchase to resale in a single bank channel with no mid-trade currency switch. Structures like the SOMO letter of credit, which routes an irrevocable payment into the CBI account at the New York Fed, need beneficiary, currency and path aligned up front, not discovered after the credit is opened.

In practice, settlement shortens from T+2 to T+1 because the three documents, contract, invoice and bill of lading, align before delivery, with the SHA-256 title fingerprint positioned upstream. The bank sees a traceable, verifiable chain rather than documents patched after the fact. Compliance is not a cost; it is the switch that turns the transfer book from relationship-based to evidence-based.