Postcodes must be a valid and entered in one of the following formats:

Format	Example Postcode
AN NAA	M1 1AA
ANN NAA	M60 1NW
AAN NAA	CR2 6XH
AANN NAA	DN55 1PT
ANA NAA	W1A 1HQ
AANA NAA	EC1A 1BB

* where A = Letter, N = Number

Note that postcodes must be entered with a space between the first and last parts.

Exceptions:
GIR 0AA is a historic postcode that was issued and does not conform to current postcode rules.
Postcodes beginning BFPO will be accepted as-is.