ZIP Codes in Acton, MA
Acton uses 2 ZIP codes, all in Middlesex County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 2 Acton ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 01718 | standard | Middlesex | 404 |
| 01720 | standard | Middlesex | 23,526 |
Finding a ZIP+4 in Acton
Knowing which of these 2 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 Acton 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 Acton addresses and download it complete.