Quote Originally Posted by bobbinville View Post
As for Kensington Palace's address -- it, like all other royal palaces and residences, does not have a street address, probably because such an address is not thought to be necessary to get mail to where it belongs.
Instead of the usual peasant's mail carrier stopping by to insert mail in the mail slot they most likely have their own private vehicle that visits the post office and takes the mail to another location for internal sorting and inspecting if this isn't already done by a post employee who has been certified personally by the 'House'.