As a box code, 2057 is used for 11 post office box locations.
PO Boxes using 2057
| Suburb | Town | Province |
|---|---|---|
| Littlefillan | Bryanston | Gauteng |
| Moodiehill | Bryanston | Gauteng |
| Morningside | Saxonwold | Gauteng |
| Morningside Ext 126 | Saxonwold | Gauteng |
| Morningside Ext 2 | Saxonwold | Gauteng |
| Morningside Ext 3 | Saxonwold | Gauteng |
| Morningside Ext 40 | Saxonwold | Gauteng |
| Morningside Ext 8 | Saxonwold | Gauteng |
| Morningside Hills | Saxonwold | Gauteng |
| Morningside Manor | Saxonwold | Gauteng |
| Morningside Manor Ext 2 | Saxonwold | Gauteng |