OL postcode area
The OL area holds 16 districts and 13,212 live postcodes; its largest place is Oldham.
| District | Live postcodes | Largest place with its centre there |
|---|---|---|
| OL1 | 777 | Shaw |
| OL2 | 1,090 | Royton |
| OL3 | 595 | Saddleworth |
| OL4 | 1,048 | Lees |
| OL5 | 370 | Mossley |
| OL6 | 898 | Ashton-under-Lyne |
| OL7 | 421 | — |
| OL8 | 849 | Oldham |
| OL9 | 972 | Chadderton |
| OL10 | 820 | Heywood |
| OL11 | 1,077 | — |
| OL12 | 1,185 | Wardle |
| OL13 | 658 | Bacup |
| OL14 | 788 | Todmorden |
| OL15 | 539 | Littleborough |
| OL16 | 1,125 | Rochdale |
Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Source: Office for National Statistics licensed under the Open Government Licence v3.0. Postcode data is the ONS Postcode Directory, August 2026 edition; counts are live postcodes with a usable location. Northern Ireland postcodes carry a separate licence and are not included; Scotland joins when the site's Scottish coverage does.