Eastern England
AL5, Harpenden, Kinsbourne Green, £587,884
LU1, South Luton and surrounding areas, £351,742
Potential saving, £236,142, 40%
East Midlands
NN12, Towcester and surrounding areas, £360,453
NN11, Daventry and surrounding areas, £300,112
Potential saving: £60,341, 17%
London
NW3, Hampstead, Belsize Park and surrounding areas, £778,767
NW2, Cricklewood, Dollis Hill and surrounding areas, £546,348
Potential saving: £232,419, 30%
North East
NE26, Whitley Bay, Seaton Sluice, £304,022
NE24, Blyth and surrounding areas, £162,075
Potential saving: £141,947, 47%
Northern Ireland
BT4 East Belfast (Sydenham, Belmont, Stormont), £278,143
BT16, Dundonald and surrounding areas, £247,068
Potential saving: £31,075, 11%
North West
WA14, Altrincham, Bowdon and surrounding areas, £403,621
M31, Carrington, Partington, £280,616
Potential saving: £123,005, 30%
Scotland
EH3, Central Edinburgh, including the West End, £374,650
EH11, Gorgie, Stenhouse and surrounding areas, £299,315
Potential saving: £75,335, 20%
South East
KT6, Surbiton, Tolworth, £625,840
KT9, Chessington, Hook, £453,441
Potential saving: £172,399, 28%
South West
BS8, Clifton, Hotwells and surrounding areas, £510,864
BS20, Portishead, Pill, £385,281
Potential saving: £125,583, 25%
Wales
CF64, Penarth, Dinas Powys, Sully, £342,753
CF63, Barry (including Cadoxton and Barry Docks), £260,234
Potential saving: £82,519, 24%
West Midlands
CV32, Leamington Spa (north) and surrounding areas, £392,988
CV35, Wellesbourne, Kineton and surrounding areas, £343,030
Potential saving: £49,958, 13%
Yorkshire and the Humber
YO23, York South Bank and surrounding areas, £378,295
YO8, Selby and surrounding areas, £243,001
Potential saving: £135,294, 36%