| 1 | UCEA | USA CARRIER ENTERPRISES LLC | | | SCAC4 |
| 2 | UCEN | UNITED CARTAGE INC | | | SCAC4 |
| 3 | UCEX | Union Electric Co. | added 10/1980; eliminated 10/1984; 1/1994 (not listed); added 1/1997; eliminated 4/1997; 7/2000-7/2005 (not listed) | | NAKINA |
| 4 | UCEX | Union Electric Co. | added 10/80; eliminated 10/84; 1/94; added 1/97; eliminated 4/97; 7/2000 | | NRHS |
| 5 | UCEX | UNION ELECTRIC COMPANY | | | PWRC |
| 6 | UCEX | Union Electric | | | RSRV |
| 7 | UCEX | UNION ELECTRIC COMPANY | | | SCAC4 |
