Русско-англо-русский юридический словарь

Legal address is used for official purposes such as for serving a notice or for tax reporting. A legal address is used to determine one’s state of legal residence and the state laws to calculate tax. A legal address may include a property’s lot number, block number or district number. (definitions.uslegal.com)

The registered office is the legal address for all limited companies registered in the UK. (Simple Formations)

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 registered office address is a legal address that can be used for receiving legal mail from the registrar in the jurisdiction in which you are registered. (Registered Address | Open a European Company)