Certificate of Registry

The certificate of registry is an official document issued by the flag state confirming the ship's nationality, the names of its owners, the vessel's identifying particulars — name, IMO number, official number, tonnage — and the port of registry. It is the primary proof of the vessel's nationality and the legal basis for it to fly the flag of the issuing state. Without a valid certificate of registry, a vessel has no recognised nationality and is effectively stateless, liable to be boarded and inspected by any naval vessel. For a master, the certificate of registry must be kept on board at all times. Port state control inspectors, coast guard authorities, and port authorities will request it as one of the first documents during any inspection or port formality. It is also required for P&I Club entry, classification, and insurance. If the vessel changes name, ownership, or port of registry, the certificate must be amended or reissued by the flag state administration. The certificate of registry is distinct from the statutory safety certificates — the Safety Construction, Safety Equipment, and Safety Radio certificates issued by the flag state under SOLAS — and from the class certificate issued by the classification society. Together, these documents form the vessel's certificate portfolio that officers must be able to produce on demand. Expired certificates — whether through oversight or failure of the flag state administration to process renewals — are a serious compliance risk.