| 1701 | HHB | Helsingør - Hornbæk Banen (Hornbækbanen) | 1906 - 1916 | DK | TRAFFIC |
| 1702 | HHB | Hamburger Hafenbahn | DE | VKM | |
| 1703 | HHBAU | W.Hundhausen Bauunternehmen GmbH | DE | VKM | |
| 1704 | HHBC | HBC HAMBURG BULK CARRIERS GMBH & CO | SCAC4 | ||
| 1705 | HHBF | HHBULKERS FIVE LTD | SCAC4 | ||
| 1706 | HHBK | H & H BROKERAGE | SCAC4 | ||
| 1707 | HHBL | HENDRIK HUDSON BUS LINES INC | SCAC4 | ||
| 1708 | HHBT | HUTTERVILLE HUTTERIAN BRETHREN | SCAC4 | ||
| 1709 | HHCC | HYDRO TECH INC | SCAC4 | ||
| 1710 | HHCE | H & H COOL EXPRESS LLC | SCAC4 | ||
| 1711 | HHCG | HUNGERFORD HEATING/ COOLING | SCAC4 | ||
| 1712 | HHCH | HH HAULING | SCAC4 | ||
| 1713 | HHCL | HEADHAUL.COM LLC | SCAC4 | ||
| 1714 | HHCO | HEINZ, H J COMPANY OF CANADA LTD | SCAC4 | ||
| 1715 | HHCR | HIS & HERS COACHWAYS INC | SCAC4 | ||
| 1716 | HHCS | HIGH HILLS COURIER SERVICE LIMITED | SCAC4 | ||
| 1717 | HHCV | H & H CONTAINER SERVICES LLC | SCAC4 | ||
| 1718 | HHCX | Flint Hills Resources LP | added 1/2009 | NAKINA | |
| 1719 | HHCX | Huntsman LLC | added 7/2003; 7/2005; eliminated 1/2009 | NAKINA | |
| 1720 | HHCX | Champlin Petroleum Co. | added 7/1965; 7/1965-4/1970; eliminated 4/1972 | NAKINA | |
| 1721 | HHCX | Champlin Oil & Refining Co. | added 4/1957; 10/1957-4/1961; eliminated 7/1965 | NAKINA | |
| 1722 | HHCX | Champlin Refining Co. | 7/1935-7/1954; eliminated 4/1957 | NAKINA | |
| 1723 | HHCX | H.H.C. Equipment Co. | 7/1932 | NAKINA | |
| 1724 | HHCX | Champlin Tank Car Co. | 7/1930 | NAKINA | |
| 1725 | HHCX | Champlin Refining Co. | 8/1920-7/1923 | NAKINA | |
| 1726 | HHCX | Champlin Refining Co. | 4/38-1/52; eliminated 4/57 | NRHS | |
| 1727 | HHCX | Champlin Oil & Refining Co. | added 4/57; 10/57-4/61; eliminated 7/65 | NRHS | |
| 1728 | HHCX | Champlin Petroleum Co. | added 7/65; 7/65-4/70; eliminated 4/72 | NRHS | |
| 1729 | HHCX | *CHAMPLIN REFINING CO. [H.H.C. EQUIPMENT CO.] | PWRC | ||
| 1730 | HHCX | +HUNTSMAN LLC | PWRC | ||
| 1731 | HHCX | Huntsman | RSRV | ||
| 1732 | HHCX | CHAMPLIN PETROLEUM CO | SCAC3 | ||
| 1733 | HHCX | HUNTSMAN LLC | SCAC4 | ||
| 1734 | HHDC | HAWG HAULING & DISPOSAL LLC | SCAC4 | ||
| 1735 | HHDK | Hjørring - Hørby | Real: HH, 1913 - 1953 | DK | TRAFFIC |
| 1736 | HHDR | HIGH DESERT TRANSPORT | SCAC4 | ||
| 1737 | HHE | Heli-Holland | ICAO1 | ||
| 1738 | HHE | Freunde der Halle-Hettstedter Eisenbahn e.V. | DE | VKM | |
| 1739 | HHEART | Hokkaido Heart Bus | J | TRAFFIC | |
| 1740 | HHEB | HILL HOPPER EXPRESS INC | SCAC4 | ||
| 1741 | HHEI | HAWK HOLLOW EXPRESS INC | SCAC4 | ||
| 1742 | HHEP | H & H EXPRESS LLC | SCAC4 | ||
| 1743 | HHER | HIRSCHE HEREFORDS | SCAC4 | ||
| 1744 | HHES | HILL, HOLLY EXPRESS LOGISTICS INC | SCAC4 | ||
| 1745 | HHEX | H & H Engineering Construction, Inc. | 7/2000-7/2005 (not listed) | NAKINA | |
| 1746 | HHEX | H & H Engineering Construction, Inc. | Jul-00 | NRHS | |
| 1747 | HHEX | H & H ENGINEERING CONSTRUCTION, INC. | PWRC | ||
| 1748 | HHEX | H and H Engineering Construction | RSRV | ||
| 1749 | HHFD | H & H FISHERIES LTD | SCAC4 | ||
| 1750 | HHFE | HUTCH FUEL OIL | SCAC4 | ||
| 1751 | HHFL | H & H FREIGHT LINES INC | SCAC4 | ||
| 1752 | HHFT | H & H FARMS | SCAC4 | ||
| 1753 | HHGB | Helsingør - Hornbæk - Gilleleje Banen (Hornbækbanen) | 1916 - 2001 | DK | jernbanen.dk |
| 1754 | HHGB | Helsingør - Hornbæk - Gilleleje Banen (Hornbækbanen) | 1916 - 2001 | DK | TRAFFIC |
| 1755 | HHGE | HOEPFNER, HANS GUENTHER | SCAC4 | ||
| 1756 | HHGI | HH & G INC | SCAC4 | ||
| 1757 | HHH | Helicsa | ICAO1 | ||
| 1758 | HHHA | H & H HAULERS | SCAC4 | ||
| 1759 | HHHF | HALPINS FUEL SERVICE INC | SCAC4 | ||
| 1760 | HHHL | HAWKINS HEAVY HAULING SERVICE LLC | SCAC4 | ||
| 1761 | HHHQ | HAWK HIGH HAULAGE INC | SCAC4 | ||
| 1762 | HHHR | HERITAGE HEAVY HAUL INC | SCAC4 | ||
| 1763 | HHHT | HENDERSON HEAVY HAUL TRUCKING INC | SCAC4 | ||
| 1764 | HHHU | KTG-KRAFTWAGEN-TRANSPORT GESMBH | SCAC3 | ||
| 1765 | HHHX | Xcel Energy | added 1/2006 | NAKINA | |
| 1766 | HHHX | Public Service Co. of Colorado | added 10/2000; eliminated 10/2002; 7/2005 (not listed) | NAKINA | |
| 1767 | HHHX | Public Service Co. of Colorado | added 10/2000 | NRHS | |
| 1768 | HHHX | XCEL ENERGY [PUBLIC SERVICE CO. OF COLORADO] | PWRC | ||
| 1769 | HHHX | Public Service of Colorado | RSRV | ||
| 1770 | HHHX | XCEL ENERGY | SCAC4 | ||
| 1771 | HHHY | HEARTLAND HEAVY HAUL INC | SCAC4 | ||
| 1772 | HHI | Hamburg International | IATA: 4R | ICAO1 | |
| 1773 | HHIB | HUGHES HEAVY INC | SCAC4 | ||
| 1774 | HHIC | HAWKES HAULING INC | SCAC4 | ||
| 1775 | HHID | HATHAWAY HAULING INC | SCAC4 | ||
| 1776 | HHIE | HOLLAND HIGHLIFT INC | SCAC4 | ||
| 1777 | HHIG | HEAVY HAULERS INC | SCAC4 | ||
| 1778 | HHIH | HIGHWAY HAULERS INC | SCAC4 | ||
| 1779 | HHIK | HICKORY HILL | SCAC4 | ||
| 1780 | HHIM | H & H IRON AND METAL INC | SCAC4 | ||
| 1781 | HHIN | HENRY & HENRY INC | SCAC4 | ||
| 1782 | HHIO | HOG HAULERS INC | SCAC4 | ||
| 1783 | HHIQ | HUDDLE HOUSE INC | SCAC4 | ||
| 1784 | HHIR | HUBBARD HALL INC | SCAC4 | ||
| 1785 | HHIY | HOLT HAULING INC | SCAC4 | ||
| 1786 | HHJ | Hads-Ning Herreders Jernbane (Odderbanen) | 1884 - 2008 | DK | jernbanen.dk |
| 1787 | HHJ | Hälsingborg - Hässleholm Järnväg | 1875 - 1940 | S | svenska-lok.se |
| 1788 | HHJ | Hads-Ning Herreders Jernbane (Odderbanen) | 1884 - 2008 | DK | TRAFFIC |
| 1789 | HHKG | H & H TRUCKING | SCAC4 | ||
| 1790 | HHKI | HATCHER TRUCKING INC | SCAC4 | ||
| 1791 | HHLA | HIGHLAND TRANSPORT INC | SCAC4 | ||
| 1792 | HHLG | H & H LOGISTICS LLC | SCAC4 | ||
| 1793 | HHLL | HAYSE HOLDINGS LLC | SCAC4 | ||
| 1794 | HHLN | HASTINGS HOT LINE TOOLS | SCAC4 | ||
| 1795 | HHLO | H & H LOGISTICAL SERVICES INC | SCAC4 | ||
| 1796 | HHLP | HOUGAR HAULING LLC | SCAC4 | ||
| 1797 | HHLU | HULL & HATCH LOGISTICS LLC | SCAC4 | ||
| 1798 | HHLW | HHL | SCAC4 | ||
| 1799 | HHLX | H & H Locomotive Leasing Inc. | 7/2005 (not listed) | NAKINA | |
| 1800 | HHLX | H & H LOCOMOTIVE LEASING, INC. | PWRC |