| 301 | HLSC | Hampton Ry., Inc. | added 10/95; 7/2000 | | NRHS |
| 302 | HLSC | HAMPTON LUMBER SALES [HAMPTON RAILWAY INC] | | | PWRC |
| 303 | HLSC | Hampton Railway | | | RSRV |
| 304 | HLSC | HAMPTON RAILWAY INC | | | SCAC4 |
| 305 | HLSD | HILL, SUSAN D | | | SCAC4 |
| 306 | HLSF | HANSEATIC LLOYD SCHIFFAHRT GMBH & C | | | SCAC4 |
| 307 | HLSG | HILLIN SAND & GRAVEL INC | | | SCAC4 |
| 308 | HLSI | HLS | | | SCAC4 |
| 309 | HLSL | HOLLAND SPECIAL LOGISTICS LLC | | | SCAC4 |
| 310 | HLSM | HONEY LOCUST FARMS LLC | | | SCAC4 |
| 311 | HLSN | HALLS INC | | | SCAC4 |
| 312 | HLSO | HILLSIDE COLONY INC | | | SCAC4 |
| 313 | HLSP | HALL'S TRANSPORT INC | | | SCAC4 |
| 314 | HLSS | HOBBY LOBBY STORES INCORPORATED | | | SCAC4 |
| 315 | HLSU | HLS CONTAINER BREMEN | | D | BIC |
| 316 | HLSU | HLS CONTAINER BREMEN | | | SCAC4 |
| 317 | HLSV | HILLSIDE VAN LINES INC | | | SCAC4 |
| 318 | HLSX | HILLSDALE RAILROAD | | | PWRC |
| 319 | HLSY | HEMISPHERE LOGISTICS & SUPPLY CHAIN | | | SCAC4 |
| 320 | HLT | Heli Transport SA | IATA: OI, Callsign: Heli Transport, | F | AVCODES |
| 321 | HLT | Helitafe | | | ICAO1 |
| 322 | HLT | Hallandstrafiken AB | | SE | VKM |
| 323 | HLTA | HOLT OIL COMPANY INC | | | SCAC4 |
| 324 | HLTC | HI-LITE TRUCK ACCESSORIES LTD | | | SCAC4 |
| 325 | HLTE | HOTLOAD TRANSPORTATION SERVICES LLC | | | SCAC4 |
| 326 | HLTF | HAMMER LANE TRUCKING | | | SCAC4 |
| 327 | HLTG | HARNETT, L T TRUCKING INC | | | SCAC4 |
| 328 | HLTJ | HLT LIMITED | | | SCAC4 |
| 329 | HLTK | H & L TRANSPORT | | | SCAC4 |
| 330 | HLTL | HOLT LOGISTICS CORP | | | SCAC4 |
| 331 | HLTM | HILTON OIL CO INC | | | SCAC4 |
| 332 | HLTN | HOLTON TRUCK LINE, INC | | | SCAC1 |
| 333 | HLTN | HLT SERVICE GROUP INC | | | SCAC4 |
| 334 | HLTO | HILLTOP TRANSPORTATION | | | SCAC4 |
| 335 | HLTP | HILLTOP OIL CO | | | SCAC4 |
| 336 | HLTQ | HOLT, STEVE CONCESSIONS | | | SCAC4 |
| 337 | HLTR | HOMELAND TRANSPORT INC | | | SCAC4 |
| 338 | HLTU | TRANS DISTANCE LINE LTD | | HK | BIC |
| 339 | HLTU | HONG XIN CHONK KONG DEVELOPMENT COM | | | SCAC4 |
| 340 | HLTV | HILLS TRUCK SERVICE | | | SCAC4 |
| 341 | HLTW | HIGHER-LEVELZ TRUCKING INC | | | SCAC4 |
| 342 | HLTX | INEOS Olefins & Polymers USA, a Division of INEOS USA LLC | added 7/2008 | | NAKINA |
| 343 | HLTX | B P Solvay Polyethylene North America | added 4/2004; 7/2005; eliminated 7/2008 | | NAKINA |
| 344 | HLTX | BP Amoco Chemical Co. | added 4/2002; eliminated 4/2004 | | NAKINA |
| 345 | HLTX | *BP SOLVAY POLYETHYLENE NORTH AMERICA {BP AMOCO; AMOCO OIL COMPANY] | | | PWRC |
| 346 | HLTX | +INEOS OLEFINS & POLYMERS USA, DIV. INEOS USA LLC | | | PWRC |
| 347 | HLTX | Amoco Oil | | | RSRV |
| 348 | HLTX | INEOS OLEFINS & POLYMERS USA A DIVI | | | SCAC4 |
| 349 | HLTY | HALTER, RANDY TRUCKING INC | | | SCAC4 |
| 350 | HLTZ | HOLLIDAY TYLER | | | PWRC |
| 351 | HLU | Heli Union Heli Prestations | Callsign: Heli Union, | F | AVCODES |
| 352 | HLU | Heli Union Heli Prestations | | | ICAO1 |
| 353 | HLUN | HALL TRUCKING | | | SCAC4 |
| 354 | HLUS | HAPAG-LLOYD USA LLC | | | SCAC4 |
| 355 | HLUU | HAESAERTS LUXEMBOURG S.A.R.L. | | L | BIC |
| 356 | HLV | Heliserv, S.A. de C.V. | Callsign: Heliserv, | MEX | AVCODES |
| 357 | HLV | Heliservicio, S.A. de C.V. | Callsign: Servi Heli, | MEX | AVCODES |
| 358 | HLVF | HILLS VAN SERVICE INC (JACKSONVILLE | | | SCAC4 |
| 359 | HLVS | HALVORSON, RALPH | | | SCAC4 |
| 360 | HLW | Heliworks Ltda. | Callsign: Heliworks, | RCH | AVCODES |
| 361 | HLW | Heliworks | | | ICAO1 |
| 362 | HLWC | HLW INC | | | SCAC4 |
| 363 | HLWE | HOWARD, LEWIS E TRUCKING INC | | | SCAC4 |
| 364 | HLWG | HOLLOWAY TRUCKING LLC | | | SCAC4 |
| 365 | HLWI | HOLWIN TOOLING SYSTEMS INC | | | SCAC4 |
| 366 | HLX | Hapag-Lloyd Executive GmbH | IATA: 3H, Callsign: Excellence, Designator 3H* recalled by IATA | D | AVCODES |
| 367 | HLX | Hapag-Lloyd Express GmbH | IATA: X3, Callsign: Excellence, | D | AVCODES |
| 368 | HLX | INAER Helicopteros | Callsign: Excellence, Designator 3H* recalled by IATA | D | AVCODES |
| 369 | HLX | Hapag-Lloyd Express GmbH | IATA: X3, Callsign: Yellow Smile, Merged into TUIFly GmbH. | D | AVCODES |
| 370 | HLX | Hapag-Lloyd Express (TUIfly) | IATA: X3 | | ICAO1 |
| 371 | HLX | North American Car Corp. | 7/1937-4/1947 | | NAKINA |
| 372 | HLX | Humane Live Stock Car Co. (North American Car Corp.) | 7/1930-7/1935 | | NAKINA |
| 373 | HLX | (North American Car Corp.) | Apr-38 | | NRHS |
| 374 | HLX | NORTH AMERICAN CAR CORP. (HUMANE LIVE STOCK CAR CO.) | | | PWRC |
| 375 | HLXA | HALL EXPRESS | | | SCAC4 |
| 376 | HLXC | HELIX COURIER LIMITED | | | SCAC4 |
| 377 | HLXI | HULL TRANSPORTATION INC | | | SCAC4 |
| 378 | HLXL | HELIX LOGISTICS LLC | | | SCAC4 |
| 379 | HLXM | HL TRANSPORTES | | | SCAC4 |
| 380 | HLXN | HALLS TRANSPORTATION | | | SCAC4 |
| 381 | HLXO | HALL TRANSPORT | | | SCAC4 |
| 382 | HLXP | HOTLINE EXPRESS LLC | | | SCAC4 |
| 383 | HLXS | HELIX SEISMIC EXPLORATION INC | | | SCAC4 |
| 384 | HLXT | HILLTRUX TANK LINES INC | | | SCAC4 |
| 385 | HLXU | HAPAG LLOYD A.G | | D | BIC |
| 386 | HLXU | HAPAG LLOYD A G | | | SCAC4 |
| 387 | HLY | Heli Air Ltd | Callsign: Whisper, | GB | AVCODES |
| 388 | HLYS | HOLLYS SUPER GAS | | | SCAC4 |
| 389 | HLYX | Holly Sugar Corp. | 1/1950-10/1966; eliminated 7/1968 | | NAKINA |
| 390 | HLYX | Holly Sugar Corp. | 1/52-10/66; eliminated 7/68 | | NRHS |
| 391 | HLYX | HOLLY SUGAR CORP. | | | PWRC |
| 392 | HLZA | HOLZMAN TRUCKING INC | | | SCAC4 |
| 393 | HLZC | HILTZ, CAM TRUCKING | | | SCAC4 |
| 394 | HLZM | HOLTZ, MIKE TRUCKING | | | SCAC4 |
| 395 | HLZN | HERMANOS LOZANO TRUCKING | | | SCAC4 |
| 396 | HLZO | HOLTZMAN OIL CORP | | | SCAC4 |
| 397 | HLZR | HILTZ MOVING & STORAGE INC | | | SCAC4 |
| 398 | HLZT | HALZIT (MARATHON ASHLAND PETROLEUM | | | SCAC4 |
