litigation heads

if someone gives you a corporate address with a postbox, does use of that postbox allow them to avoid receiving service of legal docs? 

merci

It depends,

You can serve at the company's registered office (is this distinct from their "corporate" office which doesn't have a legal meaning as such?).

IIRC companies are prohibited from having a PO box as their registered office, although I know that plenty do and I doubt it is enforced in any way at all.

So, you can serve at the registered office, which will automatically be valid. If there are other addresses for notice that you have been notified then you may as well serve there as well (included a PO box).

If the registered office is a PO box then they are in breach of company law but it doesn't affect you serving stuff against them.

Caveat to all this is that it is the rules in England. Lord knows what arcane rituals apply in Scotland, if that is relevant.

Section 1139 Companies Act is in addition to service rules as set out in CPR. 

(1) A document may be served on a company registered under this Act by leaving it at, or sending it by post to, the company's registered office.

I'm not sure that it's lawful to have a PO Box as a Registered Address, because of course you cannot 'leave' anything at a PO Box. 

A quick online check suggests that Companies House requires that together with a PO Box the company must also provide the post code of an actual location of an office.

if it was sommit "end of the world" then I would cc it to the director's addresses too. They arent always 100% po box and my cyber stalking skills used to be excellent. I letter like that to a home address ALWAYS got a response from a director (cheers for acknowledging)