Any process or notice required to be served on an oversea company to which section 691 applies is sufficiently served if addressed to any person whose name has been delivered to the registrar under preceding sections in this Part and left at or sent by post to the address which has been so delivered.
However—
where such a company makes default in delivering to the registrar the name and address of a person resident in Great Britain who is authorised to accept on behalf of the company service of process or notices, or
if at any time all the persons whose names and addresses have been so delivered are dead or have ceased so to reside, or refuse to accept service on the company's behalf, or for any reason cannot be served,
a document may be served on the company by leaving it at, or sending it by post to, any place of business established by the company in Great Britain.