| Locality | Post Code |
|---|---|
| Briantspuddle | DT2 |
| Bridge | DT10 |
| Bridport | DT6 |
| Broad Oak 2 | DT6 |
| Broadmayne | DT2 |
| Broadoak | DT10 |
| Broadwindsor | DT8 |
| Brockhill | BH20 7NH |
| Brockington | BH21 |
| Broomhill | BH21 7AR |
| Broxhill | SP6 |
| Bryanston | DT11 |
| Buckhorn Weston | SP8 |
| Buckland Newton | DT2 |
| Buckland Ripers | DT3 |
| Bucknowle | BH20 |
| Bugley | SP8 |
| Bulbarrow | DT11 0HQ |
| Bull Hill | SP6 3EF |
| Burleston | DT2 7EG |
| Burngate | BH20 5PT |
| Burstock | DT8 |
| Burton Bradstock | DT6 |
| Came | DT2 |
| Cann | SP7 |
| Cann Common | SP7 |