North London

N1 - Islington , N2 - Finchley , N3 - Church End , N4 - Finsbury Park , N5 - Highbury , N6 - Highgate , N7 - Holloway , N8 - Hornsey , N9 - Edmonton , N10 - Muswell Hill , N11 - New Southgate , N12 - North Finchley , N13 - Palmers Green , N14 - Southgate , N15 - South Tottenham , N16 - Stoke Newington , N17 - Tottenham , N18 - Upper Edmonton , N19 - Upper Holloway , N20 - Whetstone , N21 - Winchmore Hill , N22 - Wood Green

North West London

NW1 - Camden Town , NW2 - Cricklewood , NW3 - Hampstead , NW4 - Hendon , NW5 - Kentish Town , NW6 - Kilburn , NW7 - Mill Hill , NW8 - St John's Wood , NW9 - Colindale , NW10 - Willesden , NW11 - Golders Green

East London

E4 - Chingford , E5 - Clapton , E6 - East Ham , E7 - Forest Gate , E8 - Dalston , E17 - Walthamstow , E18 - South Woodford

West London

W2 - Paddington , W3 - Acton , W4 - Chiswick , W5 - Ealing , W6 - Hammersmith , W7 - Hanwell , W8 - Kensington , W9 - Maida Vale , W10 - Ladbroke Grove , W11 - Notting Hill , W12 - Shepherd's Bush , W13 - West Ealing , W14 - West Kensington

South West London

SW2 - Brixton , SW3 - Chelsea , SW4 - Clapham , SW5 - Earl's Court , SW6 - Fulham , SW7 - Kensington , SW8 - Lambeth , SW9 - Stockwell , SW10 - West Brompton , SW11 - Battersea , SW12 - Balham , SW13 - Barnes , SW14 - Mortlake , SW15 - Putney

Hertfordshire

EN1 - Enfield , EN2 - Enfield , EN3 - Enfield , EN4 - Barnet , EN5 - Barnet , EN6 - Potters Bar , EN7 - Waltham Cross , EN8 - Waltham Cross , EN9 - Broxbourne , EN10 - Hoddesdon

AL - St Albans , Harpenden , Welwyn Garden City , Hatfield

SG10 - SG14 - Hertford , Ware

WD - Watford , Kings Langley , Abbots Langley , Borehamwood , Radlett

HP - Hemel Hempstead