Paragraph 172 Service of documents or notices on any other person or entity (other than ACAS or the ACAS Arbitration Section)
If such a notice or other document is addressed, pre-paid and delivered by post—
(i)
to the addressee’s last known principal residence or, if he or she is or has been carrying on a trade, profession or business, his or her last known principal business address, or
(ii)
where the address is a body corporate, to the body’s registered or principal office,
it shall be treated as effectively served.