| 301 | Texas Secondary Oil Corporation | Devine, TX 78016 | Oil & Gas Operator | Sep 2025 |
| 302 | Texas Shallow Oil & Gas, LLC | Graham, TX 76450 | Oil & Gas Operator | Sep 2025 |
| 303 | Texas South Operating Co, Inc. | Houston, TX 77027 | Oil Operator | Sep 2025 |
| 304 | Texas Southern Petroleum Corp. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Sep 2025 |
| 305 | Texas Standard Oil Operating Co. | Midland, TX 79705 | Oil & Gas Operator | Oct 2019 |
| 306 | Texas State Oil Co. | Irving, TX 75062 | Oil & Gas Operator | Mar 2017 |
| 307 | Texas Sunset Energy And Ent Inc | Victoria, TX 77904 | Oil Operator | Aug 2003 |
| 308 | Texas Tea Oil Company | Jacksboro, TX 76458 | Oil & Gas Operator | Feb 2011 |
| 309 | Texas Trade International Inc. | Andrews, TX 79714 | Oil Operator | Sep 2025 |
| 310 | Texas United Geoproduction, Inc. | Abilene, TX 79606 | Oil & Gas Operator | Sep 2025 |
| 311 | Texas Utilities Fuel Co. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2018 |
| 312 | Texas Utilities Mining Co. | Dallas, TX 75201 | Oil & Gas Operator | May 1995 |
| 313 | Texas Valley Oil & Gas, LLC | Hidalgo, TX 78557 | Oil Operator | Sep 2025 |
| 314 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 315 | Texas Western Energy Corporation | Portland, TX 78374 | Oil & Gas Operator | Nov 2002 |
| 316 | Texas Western Oil Company | Sioux Falls, SD 57109 | Oil & Gas Operator | Sep 2013 |
| 317 | Texas, Les & Co. | Austin, TX 78746 | Oil & Gas Operator | Sep 2025 |
| 318 | Texas, Les C., LTD. | Houston, TX 77095 | Oil & Gas Operator | Dec 2006 |
| 319 | Texas-Australia Power Inc. | Wichita Falls, TX 76302 | Oil & Gas Operator | Dec 2011 |
| 320 | Texas-Ohio Producing Company | Spring, TX 77383 | Oil & Gas Operator | Jul 1995 |
| 321 | Texasgulf Inc. | Newgulf, TX 77462 | Oil & Gas Operator | Jul 1994 |
| 322 | Texcal Energy (GP) LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2016 |
| 323 | Texcal Oil Co | Cuero, TX 77954 | Oil & Gas Operator | Feb 2006 |
| 324 | Texcal Oil Inc. | Vidor, TX 77662 | Oil & Gas Operator | Jun 1994 |
| 325 | Texcal Resources, Inc. | Plano, TX 75094 | Oil & Gas Operator | Apr 1994 |
| 326 | Texcel Exploration, Inc. | Colorado SPGS, CO 80960 | Oil & Gas Operator | Sep 2025 |
| 327 | Texcrude Services LLC | Iowa Park, TX 76367 | Oil Operator | Sep 2025 |
| 328 | Texdon Operating | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 2005 |
| 329 | Texeast Operating Co., Inc. | Farmers BRNCH, TX 75234 | Oil Operator | Sep 2025 |
| 330 | Texegy Operating Company LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2024 |
| 331 | Texian Energy Corporation | Amarillo, TX 79120 | Oil & Gas Operator | Apr 1997 |
| 332 | Texian Operating Company, LLC | Irving, TX 75063 | Oil & Gas Operator | Sep 2025 |
| 333 | Texical, Inc. | Katy, TX 77491 | Oil & Gas Operator | Sep 2025 |
| 334 | Texinia Corp | Dallas, TX 75201 | Oil & Gas Operator | Jun 2015 |
| 335 | Texla Operating Co | Jonesville, TX 75659 | Oil & Gas Operator | Sep 2025 |
| 336 | Texlan Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Nov 1994 |
| 337 | Texlan Oil Company, L.C. | Tyler, TX 75711 | Oil & Gas Operator | Aug 2003 |
| 338 | Texland Petroleum Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2003 |
| 339 | Texland Petroleum, L.P. | Fort Worth, TX 76107 | Oil & Gas Operator | Sep 2025 |
| 340 | Texland Petroleum-Hobbs, L.L.C. | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2025 |
| 341 | Texland-Rector & Schumacher | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2000 |
| 342 | Texland/JMC Joint Venture | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2002 |
| 343 | Texlark Exploration Company, Inc | Plano, TX 75074 | Oil & Gas Operator | Sep 2001 |
| 344 | Texokan Energy Corporation | Scroggins, TX 75480 | Oil & Gas Operator | Jul 1996 |
| 345 | Texokan Operating, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Sep 2025 |
| 346 | Texoma Oil Tools, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2025 |
| 347 | Texon Oil Company, Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2023 |
| 348 | Texona Petroleum Corporation | Houston, TX 77084 | Oil & Gas Operator | Aug 2003 |
| 349 | Texowa, LLC | Roanoke, TX 76262 | Oil Operator | Sep 2025 |
| 350 | Texoz E&P I, Inc. | Houston, TX 77077 | Oil & Gas Operator | Sep 2025 |
| 351 | Texploration | Rosharon, TX 77583 | Oil Operator | Sep 2025 |
| 352 | Texron Operating, LLC | Bulverde, TX 78163 | Oil & Gas Operator | Sep 2025 |
| 353 | Texstar Drilling, Inc. | Houston, TX 77084 | Oil & Gas Operator | Sep 2025 |
| 354 | Texstar North America, Inc. | Waynesboro, MS 39367 | Oil & Gas Operator | Aug 1994 |
| 355 | Texstar Oil & Gas, LLC | Luling, TX 78648 | Oil & Gas Operator | Sep 2025 |
| 356 | Texstar Operating Inc. | Lubbock, TX 79423 | Oil & Gas Operator | Sep 2025 |
| 357 | Texstar Petroleum, Inc. | Houston, TX 77002 | Oil & Gas Operator | Nov 2000 |
| 358 | Texsun Operating Company Limited | Abilene, TX 79601 | Oil & Gas Operator | Mar 1996 |
| 359 | Textroleum Production, Inc. | Lubbock, TX 79452 | Oil & Gas Operator | Mar 2008 |
| 360 | Textron Southwest Inc. | Henderson, TX 75654 | Oil & Gas Operator | Sep 2025 |
| 361 | Textron Southwest L.L.C. | Addison, TX 75001 | Oil & Gas Operator | Oct 2004 |
| 362 | Texu Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Jan 2007 |
| 363 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Sep 2025 |
| 364 | Texxon Resources, Inc. | Winter Park, FL 32792 | Oil & Gas Operator | Sep 2025 |
| 365 | Texzona Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 1997 |
| 366 | TFX, Inc. | Graham, TX 76450 | Oil & Gas Operator | Oct 2019 |
| 367 | TGNR East Texas II LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 368 | TGNR East Texas LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 369 | TGNR Gulf Coast LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 370 | TGNR Panola LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 371 | TGNR TVL LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 372 | Tgo Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Dec 2008 |
| 373 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 374 | Thagard Trust | Rancho Santo, CA 92688 | Gas Operator | Sep 2025 |
| 375 | Thalmann Oil Field Service, Inc. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Mar 2008 |
| 376 | Thalmann Oilfield | Carrizo SPGS, TX 78834 | Oil Operator | Sep 2025 |
| 377 | Thalmann, David Vac Service Inc | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Sep 2025 |
| 378 | Tharp Operating Company | Houston, TX 77070 | Oil & Gas Operator | Nov 2014 |
| 379 | The Calvert Company | Oklahoma City, OK 73154-1589 | Oil & Gas Operator | Dec 2021 |
| 380 | The Cornell Corporation | Fort Worth, TX 76109 | Oil & Gas Operator | Sep 1993 |
| 381 | The Dehart Company LLC | Ardmore, OK 73402-0907 | Oil Operator | May 2025 |
| 382 | The Operating Co. | Pampa, TX 79065 | Oil & Gas Operator | Sep 2007 |
| 383 | The Quintin Little Company Inc | Ardmore, OK 73401 | Oil & Gas Operator | Jun 2025 |
| 384 | The Termo Company | Long Beach, CA 90801 | Oil & Gas Operator | Jul 2025 |
| 385 | Theisen, VIncent A. | Wilmington, DE 19807 | Oil & Gas Operator | Sep 2003 |
| 386 | Thigpin Operating, LLC | Odessa, TX 79762 | Oil Operator | Sep 2025 |
| 387 | Third Coast Energy, Inc. | Corpus Chrsti, TX 78427 | Oil & Gas Operator | Sep 2025 |
| 388 | Thomas Exploration & Devel., Inc | Jourdanton, TX 78026 | Oil & Gas Operator | Sep 2025 |
| 389 | Thomas Oil & Gas Company | Luling, TX 78648 | Oil & Gas Operator | Aug 2003 |
| 390 | Thomas Oil And Gas Inc. | San Angelo, TX 76906 | Oil & Gas Operator | May 2019 |
| 391 | Thomas Operating LTD. Co. | Dallas, TX 75220 | Oil & Gas Operator | Sep 2025 |
| 392 | Thomas Production | Electra, TX 76360 | Oil & Gas Operator | Mar 2015 |
| 393 | Thomas Resources Corporation | Monahans, TX 79756 | Oil Operator | Mar 2008 |
| 394 | Thomas, B. K. | Plano, TX 75093 | Oil & Gas Operator | Jan 2008 |
| 395 | Thomas, M.A. Oil Associates | Nocona, TX 76255 | Oil & Gas Operator | Sep 2025 |
| 396 | Thomas, Mike | Nixon, TX 78140 | Oil Operator | Sep 2025 |
| 397 | Thomas, R. W. Inc. | Norman, OK 73070 | Oil & Gas Operator | Apr 2015 |
| 398 | Thomas, T. N. Oil Company | Aiken, SC 29801 | Oil & Gas Operator | Sep 2025 |
| 399 | Thompson Oil Co. | Corsicana, TX 75151 | Oil & Gas Operator | Jun 2025 |
| 400 | Thompson Operating Co. | Abernathy, TX 79311 | Oil & Gas Operator | Aug 1994 |