This list consists of postcodes in Greater London and Outer London, which includes areas in Essex, Kent, Surrey, Middlesex and Hertfordshire.

To those unable to ascertain where these areas are in terms of geography in relation to London, this crude mapping may help:

UB | HA | EN | IG
TW | LONDON | RM
KT | SM | CR | BR | DA

where LONDON is in the centre, this is Greater London, UB (Uxbridge) is furthest NorthWest, HA (Harrow) and EN (Enfield) North of London, and IG (Ilford) to the NorthEast of London. Then TW (Twickenham) directly West of London, and RM (Romford) to the East of London, and in the SouthWest, KT (Kingston-Upon-Thames), with SM (Sutton) and CR (Croydon) South of London, and BR (Bromley) and DA (Dartford) to the far SouthEast.

In Greater London itself we have:
NW | N
W | WC | EC | E
SW | SE
Which correspond to the directions, NorthWest, North, West, West Central, East Central, East, SouthWest and SouthEast London respectively.