| Locality | Postal Code |
|---|---|
| Pine View Park | MK45 |
| Potsgrove | MK17 |
| Potton | SG19 |
| Pulloxhill | MK45 |
| Ridgmont | MK43 |
| Salford | MK17 |
| Sandy | SG19 |
| Seddington | SG19 1NU, SG19 1NZ |
| Sewell | LU6 1RP |
| Sharpenhoe | MK45 |
| Shefford | SG17 |
| Shillington | SG5 |
| Silsoe | MK45 |
| Skimpot | LU1 4AY, LU1 4AZ |
| Slip End | LU1 |
| Southill | SG18 |
| Stanbridge | LU7 |
| Stanford | SG18 |
| Steppingley | MK45 |
| Stotfold | SG5 |
| Stratton Business Park | SG18 |
| Streatley | LU3 |
| Studham | LU6 |
| Sundon | LU3 |
| Sutton | SG19 |
| Tebworth | LU7 |