| Place | Post Code |
|---|---|
| Antonie, Olszewo-Borki | 07-410 |
| Białobrzeg Bliższy, Olszewo-Borki | 07-415 |
| Białobrzeg Dalszy, Olszewo-Borki | 07-416 |
| Chojniki, Olszewo-Borki | 07-416 |
| Dobrołęka, Olszewo-Borki | 07-415 |
| Drężewo, Olszewo-Borki | 07-415 |
| Działyń, Olszewo-Borki | 07-416 |
| Grabnik, Olszewo-Borki | 07-416 |
| Grabówek, Olszewo-Borki | 07-416 |
| Grabowo, Olszewo-Borki | 07-415 |
| Kordowo, Olszewo-Borki | 07-415 |
| Kruki, Olszewo-Borki | 07-415 |
| Łazy, Olszewo-Borki | 07-410 |
| Mostówek, Olszewo-Borki | 07-416 |
| Mostowo, Olszewo-Borki | 07-416 |
| Nakły, Olszewo-Borki | 07-415 |
| Nowa Wieś, Olszewo-Borki | 07-416 |
| Nożewo, Olszewo-Borki | 07-415 |
| Olszewo-Borki, Olszewo-Borki | 07-415 |
| Przyłaje, Olszewo-Borki | 06-212 |
| Przystań, Olszewo-Borki | 07-416 |
| Rataje, Olszewo-Borki | 07-416 |
| Rżaniec, Olszewo-Borki | 07-416 |
| Siarki, Olszewo-Borki | 07-402 |
| Skrzypek, Olszewo-Borki | 07-416 |
| Stepna-Michałki, Olszewo-Borki | 07-415 |