Westminster City Area Code List
| Area Codes | Country | State | City | Time Zone | Operating |
|---|---|---|---|---|---|
| 303 | US | Colorado - CO | Westminster | Mountain | Details |
| 410 | US | Maryland - MD | Westminster | Eastern | Details |
| 443 | US | Maryland - MD | Westminster | Eastern | Details |
| 657 | US | California - CA | Westminster | Pacific | Details |
| 667 | US | Maryland - MD | Westminster | Eastern | Details |
| 714 | US | California - CA | Westminster | Pacific | Details |
| 802 | US | Vermont - VT | Westminster | Eastern | Details |
| 864 | US | South Carolina - SC | Westminster | Eastern | Details |
| 978 | US | Massachusetts - MA | Westminster | Eastern | Details |