51. (1) A document may be served on a company—

(a) by leaving it at or sending it by post to the registered office of the company; or

(b) if the company has not given notice to the Registrar of the situation of its registered office, by delivering it to the Registrar.

(2) For the purposes of this section, any document left at or sent by post to the place for the time being recorded by the Registrar as the situation of the registered office of a company shall be deemed to have been left at or sent by post to the registered office of the company notwithstanding that the situation of its registered office may have changed.

(3) It shall be the duty of the Registrar to enter on the register a document that has, by the means referred to in subsection (1)(b), been served on a company.