SN
21 districts, 14,677 postcodes
Wiltshire, Swindon, Vale of White Horse, South Gloucestershire, Cotswold, West Berkshire
| District | Postcodes | Local authority |
|---|---|---|
| SN1 | 788 | Swindon |
| SN10 | 1,204 | Wiltshire |
| SN11 | 772 | Wiltshire |
| SN12 | 824 | Wiltshire |
| SN13 | 666 | Wiltshire |
| SN14 | 972 | Wiltshire |
| SN15 | 1,310 | Wiltshire |
| SN16 | 527 | Wiltshire |
| SN2 | 956 | Swindon |
| SN25 | 821 | Swindon |
| SN26 | 74 | Swindon |
| SN3 | 1,304 | Swindon |
| SN38 | 124 | Swindon |
| SN4 | 912 | Wiltshire |
| SN5 | 899 | Swindon |
| SN6 | 680 | Swindon |
| SN7 | 562 | Vale of White Horse |
| SN8 | 940 | Wiltshire |
| SN80 | 1 | — |
| SN9 | 323 | Wiltshire |
| SN99 | 18 | Swindon |