| 1201 | HDOE | HAMILTON, DOUG | | | SCAC4 |
| 1202 | HDOI | HEIL, DON OIL CO INC | | | SCAC4 |
| 1203 | HDOL | HARDY OIL CO INC | | | SCAC4 |
| 1204 | HDON | HODGDON BROS & SONS INC | | | SCAC4 |
| 1205 | HDOP | HOODS OIL COMPANY INC | | | SCAC4 |
| 1206 | HDOT | HONDO TRUCKING INC | | | SCAC4 |
| 1207 | HDPL | HAND, PAUL | | | SCAC4 |
| 1208 | HDPU | HIMDILING PRO LTD | | RUS | BIC |
| 1209 | HDR | Helikopterdrift AS | Callsign: Helidrift, Name changed to Helitrans AS. ICAO callsign changed to Helitrans. | N | AVCODES |
| 1210 | HDR | Helitrans AS | Callsign: Helitrans, Name changed from Helikopterdrift AS. ICAO callsign changed to Helitdrift. | N | AVCODES |
| 1211 | HDR | Helikopterdrift | | | ICAO1 |
| 1212 | HDRC | HANDRICH TRUCKING INC | | | SCAC4 |
| 1213 | HDRI | HOOD TRANSPORTATION | | | SCAC4 |
| 1214 | HDRK | HINDRIKS, GEORGE | | | SCAC4 |
| 1215 | HDRM | HEIDMAR INC | | | SCAC4 |
| 1216 | HDRN | HENDRICKSON TRANSPORTATION LLC | | | SCAC4 |
| 1217 | HDRQ | H D R | | | SCAC4 |
| 1218 | HDRT | HYDRA TRANSPORT | | | SCAC4 |
| 1219 | HDRX | Helm Diamond Rail Leasing | added 10/2008 | | NAKINA |
| 1220 | HDRX | HELM DIAMOND RAIL LEASING | | | PWRC |
| 1221 | HDS | UEF Historischer Damfschnellzug e.V | | DE | VKM |
| 1222 | HDSA | HERITAGE DEDICATED SERVICES INC | | | SCAC4 |
| 1223 | HDSB | HDS EXPRESS | | | SCAC4 |
| 1224 | HDSC | HENDERSCHIED | | | SCAC4 |
| 1225 | HDSD | HACKBARTH DELIVERY SERVICE INC | | | SCAC4 |
| 1226 | HDSF | HUMPTY DUMPTY SNACK FOODS USA INC | | | SCAC4 |
| 1227 | HDSG | HARRIS DATA STORAGE INC | | | SCAC4 |
| 1228 | HDSH | HD SHIPPING LTD | | | SCAC4 |
| 1229 | HdSJ | Härnösand - Sollefteå Järnväg | 1893 - 1932 | S | svenska-lok.se |
| 1230 | HDSK | H-D-SOUCY INC | | | SCAC4 |
| 1231 | HDSL | HENDERSON LOGISTIC | | | SCAC4 |
| 1232 | HDSO | HARDISON TRANSPORTATION LLC | | | SCAC4 |
| 1233 | HDSP | HYLAND, SEAN MOTORSPORT | | | SCAC4 |
| 1234 | HDSS | HDS EXPRESS LINES | | | SCAC4 |
| 1235 | HDSU | HAYS DISTRIBUTION SERVICES LTD | | | SCAC4 |
| 1236 | HDSX | The CIT Group/Capital Finance, Inc. | added 10/2003; 7/2005 | | NAKINA |
| 1237 | HDSX | RailAmerica Equipment Corp. | added 10/1996; 7/2000; eliminated 1/2003 | | NAKINA |
| 1238 | HDSX | Huron Distribution Services/Rail America Equipment Corp. | added 7/1996; eliminated 10/1996 | | NAKINA |
| 1239 | HDSX | Huron Distribution Services | 1/1994 (not listed) | | NAKINA |
| 1240 | HDSX | H.D. Schrier | added 7/1961; 7/1965; eliminated 7/1966; added 4/1967; 4/1970; eliminated 10/1974 | | NAKINA |
| 1241 | HDSX | H.D. Schrier | 7/65; eliminated 7/66; added 4/67; 4/70; eliminated 10/74 | | NRHS |
| 1242 | HDSX | Huron Distribution Services | Jan-94 | | NRHS |
| 1243 | HDSX | Huron Distribution Services/Rail America Equipment Corp. | added 7/96; eliminated 10/96 | | NRHS |
| 1244 | HDSX | RailAmerica Equipment Corp. | added 10/96; 7/2000 | | NRHS |
| 1245 | HDSX | *H. D. SCHRIER | | | PWRC |
| 1246 | HDSX | *HURON DISTRIBUTION SERVICES | | | PWRC |
| 1247 | HDSX | +THE CIT GROUP/CAPITAL FINANCE [RAIL AMERICA EQUIPMENT CORP.] | | | PWRC |
| 1248 | HDSX | RailAmerica Equipment Corporation | | | RSRV |
| 1249 | HDSX | CIT GROUP/CAPITAL FINANCE INC, THE | | | SCAC4 |
| 1250 | HDSY | HUNTE DELIVERY SYSTEM INC | | | SCAC4 |
| 1251 | HDT | HOT DOGGER TOURS INC | | | SCAC4 |
| 1252 | HDTB | HEAVY DUTY TRANSPORT | | | SCAC4 |
| 1253 | HDTC | HURD, TRACEY | | | SCAC4 |
| 1254 | HDTD | HEAVY DUTY TRUX LTD | | | SCAC4 |
| 1255 | HDTE | HOLIDAY TREE FARMS INC | | | SCAC4 |
| 1256 | HDTH | HALVERSON, DAN TRUCKING | | | SCAC4 |
| 1257 | HDTI | HERMAN, DANNY TRUCKING INC | | | SCAC4 |
| 1258 | HDTK | HOOD TRUCKING | | | SCAC4 |
| 1259 | HDTM | H D T | | | SCAC4 |
| 1260 | HDTN | HEAVY DUTY TRANSAXLE INC | | | SCAC4 |
| 1261 | HDTT | HANNAH, DAVID TRANSPORTATION | | | SCAC4 |
| 1262 | HDTX | Sun Products Corp. | added 1/2009 | | NAKINA |
| 1263 | HDTX | Huish Detergents, Inc. | added 4/2007; eliminated 1/2009 | | NAKINA |
| 1264 | HDTX | HUISH DETERGENTS, INC. | | | PWRC |
| 1265 | HDTX | SUN PRODUCTS CORPORATION | | | SCAC4 |
| 1266 | HDUG | DHUGGA TRUCKING LTD | | | SCAC4 |
| 1267 | HDVF | HDVS FREIGHT SYSTEMS INC | | | SCAC4 |
| 1268 | HDVS | HOLIDAY VAN & STORAGE | | | SCAC4 |
| 1269 | HDW | Hafendienste Wilhelmshaven GmbH | Wilhelmshafen | D | privat-bahn.de |
| 1270 | HDWC | HEADWIN LOGISTICS CO LTD | | | SCAC4 |
| 1271 | HDWE | HODGINS, DWAYNE | | | SCAC4 |
| 1272 | HDWH | HICKMAN, DALE W HAULING | | | SCAC4 |
| 1273 | HDWL | HADDIX, WILLIAM | | | SCAC4 |
| 1274 | HDX | Hooker-Detrex Inc. | 1/1950-7/1954; eliminated 10/1956 | | NAKINA |
| 1275 | HDX | Hooker-Detrex Inc. | Jan-52 | | NRHS |
| 1276 | HDX | HOOKER-DETREX INC. | | | PWRC |
| 1277 | HDXC | HERDRICH TRANSPORT LLC | | | SCAC4 |
| 1278 | HDXL | HD TRANSPORTATION LLC | | | SCAC4 |
| 1279 | HDXN | HILLSIDE TRANSPORT INC | | | SCAC4 |
| 1280 | HDXO | HENDRIX OIL INC | | | SCAC4 |
| 1281 | HDXS | HAMMOND TRANSPORTATION INC | | | SCAC4 |
| 1282 | HDXU | HDS LINES | | | SCAC4 |
| 1283 | HDYC | HANDY TRUCKING COMPANY LLC | | | SCAC4 |
| 1284 | HDYE | HARDY, EARL TRUCKING INC | | | SCAC4 |
| 1285 | HDYK | HEAVY DUTY TRUCKERS LLC | | | SCAC4 |
| 1286 | HDYL | HUB DELIVERY INC | | | SCAC4 |
| 1287 | HDYO | HARDY OIL TRANSPORT | | | SCAC4 |
| 1288 | HE | LGW-Luftfahrtgesellschaft Walter GmbH | ICAO: LGW, Callsign: Walter, Filed for insolvency on 22 April 2020. | D | AVCODES |
| 1289 | HE | Hollis & Eastern R.R. Co. | 1/1975-7/2005 | | NAKINA |
| 1290 | HE | Hartford Eastern Ry. | 7/1923-7/1932 | | NAKINA |
| 1291 | HE | Hollis & Eastern R.R. Co. | 1/75-7/2000 | | NRHS |
| 1292 | HE | Historische Eisenbahn e.V. | Frankfurt | D | privat-bahn.de |
| 1293 | HE | *HARTFORD EASTERN RWY. | | | PWRC |
| 1294 | HE | +HOLLIS & EASTERN RAILROAD | | | PWRC |
| 1295 | HE | Hollis and Eastern Railroad | | | RSRV |
| 1296 | HE | HOLLIS & EASTERN R R CO | | | SCAC4 |
| 1297 | HE | Hollis & Eastern R.R. Co. | | USA | TRAFFIC |
| 1298 | HE | Hugo Ehlers GmbH & Co Kg | | DE | VKM |
| 1299 | HEA | Heliavia-Transporte Aereo, Lda | Callsign: Heliavia, | P | AVCODES |
| 1300 | HEA | The Hawaii Express | IATA: LP, Ceased operations | USA | AVCODES |
