ZIP Codes in New Castle, PA
New Castle uses 3 ZIP codes, all in Lawrence County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 3 New Castle ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 16101 | standard | Lawrence | 30,767 |
| 16102 | standard | Lawrence | 4,929 |
| 16105 | standard | Lawrence | 15,418 |
Finding a ZIP+4 in New Castle
Knowing which of these 3 ZIP codes covers an address only gets you partway. The four-digit extension identifies the specific delivery point — typically one side of one block. Two houses facing each other on the same New Castle street almost always have different ZIP+4 codes even though they share all five leading digits.
Appending ZIP+4 to a mailing list?
Upload a CSV of New Castle addresses and download it complete.