SL postcode area
The SL area holds 12 districts and 10,672 live postcodes; its largest place is Slough.
| District | Live postcodes | Largest place with its centre there |
|---|---|---|
| SL0 | 345 | Iver Heath |
| SL1 | 1,654 | Slough |
| SL2 | 1,132 | Upton Lea |
| SL3 | 1,077 | Colnbrook |
| SL4 | 1,376 | Windsor |
| SL5 | 888 | Ascot |
| SL6 | 2,316 | Maidenhead |
| SL7 | 695 | Marlow |
| SL8 | 264 | Bourne End |
| SL9 | 872 | Gerrards Cross |
| SL60 | 30 | — |
| SL95 | 23 | — |
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.