| Locality | Postal Code |
|---|---|
| Postal/ZIP Codes in Askim, Indre Østfold | 1807, 1808, 1809, 1811, 1812, … |
| Postal/ZIP Codes in Båstad, Indre Østfold | 1866 |
| Postal/ZIP Codes in Eidsberg, Indre Østfold | 1880 |
| Postal/ZIP Codes in Hærland, Indre Østfold | 1878 |
| Postal/ZIP Codes in Hobøl, Indre Østfold | 1827 |
| Postal/ZIP Codes in Knapstad, Indre Østfold | 1823 |
| Postal/ZIP Codes in Mysen, Indre Østfold | 1850, 1852 |
| Postal/ZIP Codes in Slitu, Indre Østfold | 1859 |
| Postal/ZIP Codes in Spydeberg, Indre Østfold | 1820, 1821 |
| Postal/ZIP Codes in Tomter, Indre Østfold | 1825 |
| Postal/ZIP Codes in Trøgstad, Indre Østfold | 1860 |