All postcodes in SS99 1
| Postcode | Place | Type |
|---|---|---|
| SS99 1AA | Southend-on-Sea | large user |
| SS99 1BF | Southend-on-Sea | large user |
| SS99 1BH | Southend-on-Sea | large user |
| SS99 1BL | Southend-on-Sea | large user |
| SS99 1NN | Southend-on-Sea | large user |
| SS99 1WF | — | large user |
| SS99 1WL | Southend-on-Sea | large user |
| SS99 1ZZ | Southend-on-Sea | large user |