All postcodes in W1B 3
| Postcode | Place | Type |
|---|---|---|
| W1B 3AA | City of Westminster | street |
| W1B 3AF | City of Westminster | street |
| W1B 3AG | City of Westminster | street |
| W1B 3AH | City of Westminster | street |
| W1B 3AP | City of Westminster | street |
| W1B 3AQ | City of Westminster | street |
| W1B 3AS | City of Westminster | street |
| W1B 3AT | City of Westminster | street |
| W1B 3AU | City of Westminster | street |
| W1B 3BJ | City of Westminster | street |
| W1B 3BL | City of Westminster | street |
| W1B 3BN | City of Westminster | street |
| W1B 3BR | City of Westminster | street |
| W1B 3DA | City of Westminster | street |
| W1B 3DB | City of Westminster | street |
| W1B 3DE | City of Westminster | street |
| W1B 3DG | City of Westminster | street |
| W1B 3HH | City of Westminster | large user |