| PEOPLES GAS COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | May 31, 1950 | Inactive |
| TECO BARGE LINE, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Mar 4, 1959 | Inactive |
| TECO OCEAN SHIPPING, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Mar 4, 1959 | Inactive |
| TECO STEVEDORING SERVICES, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Sep 2, 1964 | Inactive |
| PRIOR ENERGY CORPORATIONTampa, FL · Inactive | Tampa, FL | Corporation | Nov 27, 2001 | Inactive |
| PRIOR INTRASTATE CORPORATIONTampa, FL · Inactive | Tampa, FL | Corporation | Nov 27, 2001 | Inactive |
| TECO TRANSPORT CORPORATIONTampa, FL · Inactive | Tampa, FL | Corporation | Nov 2, 1981 | Inactive |
| TECO TOWING COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | Jul 18, 1983 | Inactive |
| PEOPLES COGENERATION COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | May 20, 1985 | Inactive |
| TECO INVESTMENTS, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | May 4, 1987 | Inactive |
| TECO GAS SERVICES, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Sep 8, 1987 | Inactive |
| SUWANNEE GAS MARKETING, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Sep 10, 1987 | Inactive |
| TERMCO, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Oct 15, 1987 | Inactive |
| PEOPLES SALES & SERVICE COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | Dec 5, 1988 | Inactive |
| CPSC, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Jun 30, 1989 | Inactive |
| TECO SYNFUEL ADMINISTRATION, LLCTampa, FL · Inactive | Tampa, FL | LLC | Dec 18, 2007 | Inactive |
| SLA 75, LLCTampa, FL · Inactive | Tampa, FL | LLC | Nov 14, 2016 | Inactive |
| TPS OPERATIONS COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | Dec 21, 1989 | Inactive |
| LAKE COUNTY POWER RESOURCES, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Dec 21, 1989 | Inactive |
| TPS CLEAN COAL, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Dec 21, 1989 | Inactive |
| H POWER II, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Mar 21, 1990 | Inactive |
| H POWER I, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Mar 21, 1990 | Inactive |
| TECO ENERGY FOUNDATION, INC.Tampa, FL · Inactive | Tampa, FL | Nonprofit | Dec 10, 2001 | Inactive |
| TECO PROPANE PROPERTIES, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Jan 28, 2000 | Inactive |
| TPS MATERIALS, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Apr 17, 2000 | Inactive |
| TECO SOLUTIONS, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Aug 7, 2000 | Inactive |
| TECO POWER VENTURES, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Oct 23, 2000 | Inactive |
| TPS GP, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Oct 24, 2000 | Inactive |
| TPS LP, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Oct 24, 2000 | Inactive |
| TPS HOLDINGS II, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Jan 30, 2001 | Inactive |
| TECO COMMERCE, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Feb 12, 2001 | Inactive |
| TPS GP II, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Feb 16, 2001 | Inactive |
| TPS LP II, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Feb 16, 2001 | Inactive |
| TPS ARIZONA OPERATIONS COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | Mar 12, 2001 | Inactive |
| TPS OPERATIONS HOLDING COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | Aug 6, 2001 | Inactive |
| TPS MCADAMS OPERATIONS COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | Aug 7, 2001 | Inactive |
| TPS DELL OPERATIONS COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | Aug 7, 2001 | Inactive |
| TPS FRONTERA OPERATIONS I, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Aug 28, 2002 | Inactive |
| TPS FRONTERA OPERATIONS II, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Sep 10, 2002 | Inactive |
| TECO FIBER, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Dec 19, 2002 | Inactive |
| TWG MERCHANT, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | May 4, 2004 | Inactive |
| TECO CONSUMER HOLDINGS, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Jul 23, 2009 | Inactive |
| TECO CONSUMER VENTURESTampa, FL · Inactive | Tampa, FL | Corporation | Jul 23, 2009 | Inactive |
| TPS HOLDINGS, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | May 25, 1994 | Inactive |
| TECO INVENTORY COMPANYTampa, FL · Inactive | Tampa, FL | Corporation | Oct 28, 1994 | Inactive |
| TPS GUATEMALA ONE, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Nov 22, 1994 | Inactive |
| UTC II, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Feb 16, 1995 | Inactive |
| POWER ENGINEERING & CONSTRUCTION, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Sep 9, 1996 | Inactive |
| BGA SPECIAL PROJECT ONE, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | Apr 10, 1997 | Inactive |
| PASCO POWER GP, INC.Tampa, FL · Inactive | Tampa, FL | Corporation | May 13, 1997 | Inactive |