If you choose to use a SAIL address for your limited company, it must be situated in the same country as your registered office. So, as long as your business address meets this requirement, it can be used as a SAIL address. However, please be aware that your SAIL address will be displayed on public record.
You must tell Companies House as soon as possible when you start using a SAIL address and what records you are moving there from your registered office. You can notify them online or by post using forms AD02 and AD03.
Alternatively, if you registered your company through a formation agent, you can login to your online client account and file the information electronically without a form.