| Code | Name | Region |
|---|---|---|
| USQZQ | Charlotte | NY |
| USKHL | Charlotte | TN |
| USTX2 | Charlotte | TX |
| USJCA | Charlotte | VT |
| USJTH | Charlotte Hall | MD |
| USCHO | Charlottesville | VA |
| USCA6 | Charlton | MA |
| USCA8 | Charm | OH |
| USCQO | Charter Oak | CA |
| USC9E | Chase | KS |
| USHSY | Chase City | VA |
| USHXL | Chase Mills | NY |
| USACM | Chaska | MN |
| USVSL | Chassell | MI |
| USCUX | Chateaugay | NY |
| USCF7 | Chatfield | MN |
| USCYM | Chatham | AK |
| USCZ7 | Chatham | IL |
| USZB4 | Charleston | AR |
| USILC | Charleston | IL |
| US8ES | Charleston | ME |
| USCXS | Charleston | MO |
| USHRS | Charleston | MS |
| USNCS | Charleston | NC |
| USCJT | Charleston | OR |
| USYI3 | Charleston | PA |
| USCHS | Charleston | SC |
| USCTC | Charleston | TN |
| USCST | Charleston | TX |
| USC84 | Charleston | UT |
| USCRW | Charleston | WV |
| USZGT | Charleston Heights | SC |
| USC64 | Charleston Springs | NJ |
| USXEK | Charlestown | IN |
| USCHN | Charlestown | MA |
| USZJD | Charlestown | NH |
| USCJW | Charlestown | RI |
| USCSX | Charlevoix | MI |
| USCA4 | Channing | TX |
| USCYL | Chantilly | VA |
| USCNU | Chanute | KS |
| USCHE | Chapel Hill | NC |
| USCIH | Chapel Hill | TN |
| USCAI | Chapin | SC |
| US6NC | Chaplin | CT |
| USCEP | Chapman | AL |
| US9CP | Chapman | KS |
| USCP7 | Chapman | NE |
| USCB4 | Chapmansboro | TN |
| USVCH | Chapmanville | WV |