What was RMS Titanic's British official number?

RMS Titanic's British official number was 131428.

This was the vessel's registration identifier in the British shipping system, not her shipyard number. Titanic was registered at Liverpool in March 1912, shortly before beginning her maiden voyage, and official records list her as a British steamship owned by the Oceanic Steam Navigation Company, better known as the White Star Line.

The number is easy to confuse with other identifiers. Titanic's Harland and Wolff yard number was 401, while her wireless call sign was HVMP and her distress call sign was MGY. Her sister ship Olympic had the nearby British official number 131346, which may explain one of the tempting alternatives.

The number appears in the British Board of Trade inquiry, passenger certificates, crew agreements and contemporary registry documents. Those records also connect it with Liverpool registration, gross tonnage of about 46,328 tons and Titanic's triple-screw design. Titanic sank on 15 April 1912 after striking an iceberg during her maiden voyage from Southampton to New York.