ZIP Code 18003 is located in Lehigh Valley Pennsylvania. 18003 is entirely within Northampton County. Regionally, 18003 is located in Metro Philadelphia.
| ZIP Code Name | Lehigh Valley |
| Primary County | Northampton County |
| ZIP Code Type | Unique |
| Current Time | EST |
| Coordinates | 40.67283630,-75.37936401 |
| Adjacent ZIP Codes | |
| Region | Metro Philadelphia |
| Metropolitan/Micropolitan Stat Area | Allentown-Bethlehem-Easton, PA-NJ |
| Time Zone | Eastern Standard Time |
| IANA Timezone | America/New_York |