In MIN 379 (Ship Security Officer: Recognition) the MCA states that it will accept an SSO certificate issued by another Administration if:
(1) the MCA already accepts that country’s Certificates of Competency towards the issue of UK CECs; and (2) the SSO Certificate is issued under STCW Code A-VI/5. MIN 379 lists EU/EEA and non-EU/EEA countries whose CoCs were (in February 2010) accepted by the MCA. Because that list may have since been updated, the MCA’s website should be consulted for the current list, or the MCA should be contacted to check for any update.