One of 124 postal areas denoted by a 1 or 2 alphabetic code usually based on large cities e.g. B (Birmingham), CV (Coventry).
Comprises the Outward and Inward elements of the postal code used for mail sortation. Approx 15 households per postcode.
The Postcode District used for outward sortation of mail, e.g. CV34 with average of 8,000 households.
Partial postcode including first numeric character after space e.g. CV34 5 with average of 2,000 households.