ZIP Codes in Janesville, IA
Janesville uses 1 ZIP code, all in Bremer County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 1 Janesville ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 50647 | standard | Bremer | 1,978 |
Finding a ZIP+4 in Janesville
Knowing which of these 1 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 Janesville 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 Janesville addresses and download it complete.