| HA0 |
WEMBLEY |
Wembley Central (west), North Wembley, Alperton, Sudbury (south) |
Brent, Ealing, Harrow |
| HA1 |
HARROW |
Harrow, Harrow on the Hill, North Harrow, Northwick Park, Sudbury (north), Sudbury Hill |
Brent, Harrow |
| HA2 |
HARROW |
North Harrow, South Harrow, West Harrow, Headstone, Rayners Lane (south) |
Harrow |
| HA3 |
HARROW |
Harrow Weald, Kenton, Wealdstone, Queensbury, Belmont (west and south) |
Brent, Harrow |
| HA4 |
RUISLIP |
Ruislip, Eastcote (west and south), South Ruislip, Ruislip Manor, Ruislip Gardens |
Hillingdon |
| HA5 |
PINNER |
Pinner, Eastcote (north and east), Hatch End, Rayners Lane (north), Carpenders Park (part) |
Harrow, Hillingdon, Three Rivers |
| HA6 |
NORTHWOOD |
Northwood, Northwood Hills, Moor Park |
Hillingdon, Three Rivers |
| HA7 |
STANMORE |
Stanmore, Queensbury, Belmont (north and east) |
Brent, Harrow |
| HA8 |
EDGWARE |
Edgware, Burnt Oak, Canons Park, Queensbury |
Barnet, Brent, Harrow |
| HA9 |
WEMBLEY |
Wembley Central (east), Wembley Park, Preston, Tokyngton |
Brent |