Русско-англо-русский юридический словарь

Firstly, you may not know what a registered office address is. It is simply the legal address of the company that Companies House and HMRC will have on their records, in fact Section 86 of the Companies Act 2006 states that “a company must at all times have a registered office which all communications and notices may be addressed” (I-Support Business)

A Company Registration Number (CRN), also known as a “Companies House Number” or “Company Number,” is a unique identifier assigned to limited companies and LLPs when they are registered with Companies House. (yourcompanyformations.co.uk)