Well, the code was CM7 5PL - Just up the road from me Auntie Flo at Bocking Mill. Well, it would be if she hadn't died half a century ago. Anyway, the venue was The Fennes in Fennes Road, so the house being the road name may have blown the TT's little brain.
I'm 99% sure we tried the Post Code with no space.
The use of the term ZIP may be just a bit of American detritus but as mentioned, that did remain alongside the Union flag.
Oh, American ZIP codes have XXXXX-XXXX for the full address. I'm not sure if it is deemed part of the accepted term ZIP however. Very little of my incoming mail used the full set.