A company’s registered office address has to be in the UK. More specifically, it has to be in England or Wales for a company registered in either England or wales and it has to be in Scotland for companies registered in Scotland.
The registered address is where all official correspondence from Companies House & HMRC will be sent. It can be different from your trading address.
It could be your home address, the trading address or a purchased registered office address if you do not want your personal address to be public, or if you are after a more prestigious address such as a London Registered Address.