| Locality | Post Code |
|---|---|
| Arden, New Castle | 19810 |
| Bear, New Castle | 19701 |
| Bellefonte, New Castle | 19809 |
| Blackbird, New Castle | 19734 |
| Christiana, New Castle | 19702 |
| Claymont, New Castle | 19703 |
| Delaware City, New Castle | 19706 |
| Edgemoor, New Castle | 19809 |
| Elsmere, New Castle | 19805 |
| Greenville, New Castle | 19807 |
| Historic New Castle, New Castle | 19720 |
| Hockessin, New Castle | 19707 |
| Kirkwood, New Castle | 19708 |
| Manor, New Castle | 19720 |
| Marshallton, New Castle | 19808 |
| Middletown, New Castle | 19709 |
| Minquadale, New Castle | 19720 |
| Montchanin, New Castle | 19710 |
| New Castle, New Castle | 19720, 19726 |
| Newark, New Castle | 19702, 19711, 19712, 19713, 19716, … |
| Newport, New Castle | 19804 |
| Odessa, New Castle | 19730 |
| Port Penn, New Castle | 19731 |
| Rockland, New Castle | 19732 |
| Saint Georges, New Castle | 19733 |
| Stanton, New Castle | 19804 |
| Delaware Postal Codes | |
|---|---|
| Sussex | New Castle |
| Kent | |