The forex bureau requires one offshore back-to-back deal to be handled at one bank in one currency; switching needs the 'special offshore back-to-back' remark and a five-business-day report. SNSUC signs through an offshore SPV and transfers title to the refiner, which clears customs on its own quota.

The combination of two-step declaration (release against a guarantee with documents filed later) and consolidated duty payment compresses the transit working-capital cycle of STS anchorage transshipment. For SNSUC's structure of an offshore SPV as supplier with STS-locked discharge ports, the cash-flow window widens materially.