| Locality | Post Code |
|---|---|
| Aduard, Westerkwartier | 9831 |
| Boerakker, Westerkwartier | 9359, 9361, 9362 |
| Briltil, Westerkwartier | 9805 |
| De Wilp, Westerkwartier | 9367 |
| Den Ham, Westerkwartier | 9833 |
| Den Horn, Westerkwartier | 9832 |
| Doezum, Westerkwartier | 9863 |
| Enumatil, Westerkwartier | 9811, 9812 |
| Ezinge, Westerkwartier | 9891 |
| Feerwerd, Westerkwartier | 9892 |
| Garnwerd, Westerkwartier | 9893 |
| Grijpskerk, Westerkwartier | 9843 |
| Grootegast, Westerkwartier | 9861 |
| Jonkersvaart, Westerkwartier | 9366 |
| Kommerzijl, Westerkwartier | 9881, 9882 |
| Kornhorn, Westerkwartier | 9864 |
| Lauwerzijl, Westerkwartier | 9885 |
| Leek, Westerkwartier | 9351 |
| Lettelbert, Westerkwartier | 9827 |
| Lucaswolde, Westerkwartier | 9825 |
| Lutjegast, Westerkwartier | 9866 |
| Marum, Westerkwartier | 9363 |
| Midwolde, Westerkwartier | 9355 |
| Niebert, Westerkwartier | 9365 |
| Niehove, Westerkwartier | 9884 |
| Niekerk, Westerkwartier | 9822 |
| Groningen Postal Codes | |
|---|---|
| Westerwolde | Westerkwartier |
| Veendam | Stadskanaal |
| Pekela | Oldambt |
| Midden-Groningen | Loppersum |
| Het Hogeland | Groningen |
| Delfzijl | Appingedam |