Uploader's Comments

This is almost the only London postal area not in London, E4 is split between Chingford, in London, and Sewardstone, which is still in the postal district but in Essex. The borders have changed a few times in the 20th century but this has always been the main example, the only other now being a small corner of NW7 which is in Hertfordshire, and has recently been reduced in size but not removed entirely.