As a box code, 5400 is used for 23 post office box locations.
PO Boxes using 5400
| Suburb | Town | Province |
|---|---|---|
| Acton Caba | Tsomo | Eastern Cape |
| Coopersdrift | Tsomo | Eastern Cape |
| Dotyeni | Tsomo | Eastern Cape |
| Four Pines | Tsomo | Eastern Cape |
| Garner's Drift | Tsomo | Eastern Cape |
| Gomoro | Tsomo | Eastern Cape |
| Hange | Tsomo | Eastern Cape |
| Kwanazo | Tsomo | Eastern Cape |
| Low Valley | Tsomo | Eastern Cape |
| Makwababa | Tsomo | Eastern Cape |
| Matzotshweni | Tsomo | Eastern Cape |
| Mbulukweza | Tsomo | Eastern Cape |
| Mncedi | Tsomo | Eastern Cape |
| Mount Mist | Tsomo | Eastern Cape |
| Nelverton | Tsomo | Eastern Cape |
| Ngqwaru | Tsomo | Eastern Cape |
| Njombo | Tsomo | Eastern Cape |
| Nqumakala | Tsomo | Eastern Cape |
| Ntsito | Tsomo | Eastern Cape |
| Qumanco | Tsomo | Eastern Cape |
| Qutsa | Tsomo | Eastern Cape |
| Sigubudwini | Tsomo | Eastern Cape |
| Tsomo | Tsomo | Eastern Cape |