Default Americansied contact info?

Quite surprised and a bit annoyed that the contact info, in particular the Address field, is Americanised... I cant even add our Post Code into the Zip Code as its a numeric field only! Is there a way to change this, or define my own fields?

Its almost as bad as not seeing English (United Kingdom) and only English (American) when installing software... there's a difference between the two, and surely the clue is in the name itself!