Can I change the word "unit" in my address

Yes, you can replace the word "Unit" with anything you like. For example: Building, Suite, Room or even remove it completely as long as your client number is still displayed.

Here are some examples:
(Name), Unit *****, PO Box 6XXX, London, W1A XXX
(Name), Suite *****, PO Box 6XXX, London, W1A XXX
(Name), Building *****, PO Box 6XXX, London, W1A XXX