| 1801 | AC | Algoma Central R.R., Inc. | added 4/1995 | | NAKINA |
| 1802 | AC | Algoma Central Ry. | 10/1966-1/1994; eliminated 4/1995 | | NAKINA |
| 1803 | AC | Algoma Central & Hudson Bay Ry. Co. | 7/1923-7/1965 | | NAKINA |
| 1804 | AC | Algoma Central & Hudson Bay Ry. Co. | 7/23-7/65 | | NRHS |
| 1805 | AC | Algoma Central Ry. | 10/66-1/94; eliminated 4/95 | | NRHS |
| 1806 | AC | Algoma Central R.R., Inc. | added 4/95 | | NRHS |
| 1807 | AC | Algoma Central Ry., Inc. | added 10/95; 7/2000 | | NRHS |
| 1808 | AC | *ATLANTIC CITY RAILROAD | | | PWRC |
| 1809 | AC | +ALGOMA CENTRAL RAILWAY (CANADIAN NATIONAL RWY.) [ALGOMA CENTRAL & HUDSON BAY RY. CO.] | | | PWRC |
| 1810 | AC | Algoma Central and Hudson Bay Railway (Algoma Central Railway) | | | RSRV |
| 1811 | AC | ALGOMA CENTRAL RAILROAD INC | | | SCAC4 |
| 1812 | AC | Algoma Central | | USA | TRAFFIC |
| 1813 | AC&Y | NORFOLK SOUTHERN [AKRON, CANTON & YOUNGSTON RAILROAD] | | | PWRC |
| 1814 | ACA | Air Canada | IATA: AC, Callsign: Air Canada, IATA Prefix: 014, | CDN | AVCODES |
| 1815 | ACA | Air Canada | IATA: AC | | ICAO1 |
| 1816 | ACA | ALUMINUM COMPANY OF AMERICA (ALCOA) | | | PWRC |
| 1817 | ACA | Air Canada | | CDN | TRAFFIC |
| 1818 | ACAA | AMER-CANA GALLERIES | | | SCAC4 |
| 1819 | ACAB | AMERICAN CAB CO | | | SCAC3 |
| 1820 | ACAB | ACROLAB LTD | | | SCAC4 |
| 1821 | ACAC | ACACIA VAN & STORAGE CO | | | SCAC3 |
| 1822 | ACAD | ACADEMY VAN & STORAGE COMPANY, INC | | | SCAC3 |
| 1823 | ACAD | ACADEMY VAN & STORAGE COMPANY, INC | | | SCAC4 |
| 1824 | ACAD | Academy Bus Lines | Real: ACADEMY | USA | TRAFFIC |
| 1825 | ACAE | AMERICAN CARTAGE AGENCY LTD | | | SCAC4 |
| 1826 | ACAF | A A CARRIERS INC | | | SCAC3 |
| 1827 | ACAG | ACTION AIR SERVICES INC | | | SCAC3 |
| 1828 | ACAG | AUTOTRANSPORTES DE CARGA AGUILAS DE | | | SCAC4 |
| 1829 | ACAH | ACCA TRUCKING INC | | | SCAC3 |
| 1830 | ACAI | ALL-CAL TOURS INC | | | SCAC3 |
| 1831 | ACAI | ALTAMIRANO CAMPOS, ISRAEL | | | SCAC4 |
| 1832 | ACAJ | A C T INC | | | SCAC3 |
| 1833 | ACAK | A C A TRUCKING CO INC | | | SCAC3 |
| 1834 | ACAL | ACTION CARTAGE INC | | | SCAC3 |
| 1835 | ACAM | AMERICAN RAMP TRANSIT INC | | | SCAC4 |
| 1836 | ACAN | ACTION AMERICAN CHARTER COACHES | | | SCAC3 |
| 1837 | ACAN | ACAN WINDOW SYSTEMS INC | | | SCAC4 |
| 1838 | ACAO | ACTIVE MOVING AND STORAGE | | | SCAC3 |
| 1839 | ACAO | AHTICAL TRANSPORT INC | | | SCAC4 |
| 1840 | ACAP | ACE & ACME INC | | | SCAC3 |
| 1841 | ACAP | ACAM TRANSPORT INC | | | SCAC4 |
| 1842 | ACAQ | ACE CARTAGE CO | | | SCAC3 |
| 1843 | ACAQ | ARMOIRES CUISINES ACTION | | | SCAC4 |
| 1844 | ACAR | AIR CARGO AMERICA MOTOR | | | SCAC3 |
| 1845 | ACAR | AMERICAN CARGOES INC | | | SCAC4 |
| 1846 | ACAS | ACE MOVING & STORAGE INC | | | SCAC3 |
| 1847 | ACAS | AIR CARGO EXPRESS | | | SCAC4 |
| 1848 | ACAT | ARMENTROUT TRUCK LINE | | | SCAC3 |
| 1849 | ACAT | ABSOLUTE COURIER & TRANSPORT INC | | | SCAC4 |
| 1850 | ACAU | ARCTIC CONTAINER OY | | FIN | BIC |
| 1851 | ACAU | ARAWAK CARIBBEAN LINE LTD. | | | SCAC3 |
| 1852 | ACAU | ARCTIC CONTAINER OY | | | SCAC4 |
| 1853 | ACAW | AMERICAL TRANSPORT INC | | | SCAC3 |
| 1854 | ACAX | Honeywell International, Inc. | added 7/2000; 7/2000-7/2005 | | NAKINA |
| 1855 | ACAX | AlliedSignal Inc. | added 1/1999; eliminated 7/2000 | | NAKINA |
| 1856 | ACAX | Allied Chemical Co. (Allied Corp.) | added 7/1993; eliminated 1/1999 | | NAKINA |
| 1857 | ACAX | Allied Chemicals Canada, Inc. | added 10/1988; eliminated 7/1993 | | NAKINA |
| 1858 | ACAX | Allied Canada, Ltd. | added 7/1987; eliminated 10/1988 | | NAKINA |
| 1859 | ACAX | Allied Chemical, a Division of Allied Canada, Inc. | added 5/1983; 1/1985; eliminated 7/1987 | | NAKINA |
| 1860 | ACAX | Allied Chemical Canada, Ltd. | eliminated 5/1983 | | NAKINA |
| 1861 | ACAX | Aluminum Co. of America | 7/1923 | | NAKINA |
| 1862 | ACAX | Allied Chemical Canada, Ltd. | eliminated 5/83 | | NRHS |
| 1863 | ACAX | Allied Chemical, a Division of Allied Canada, Inc. | added 5/83; eliminated 7/87 | | NRHS |
| 1864 | ACAX | Allied Canada, Ltd. | added 7/87; eliminated 10/88 | | NRHS |
| 1865 | ACAX | Allied Chemicals Canada, Inc. | added 10/88; eliminated 7/93 | | NRHS |
| 1866 | ACAX | Allied Chemical Co. (Allied Corp.) | added 7/93; eliminated 1/99 | | NRHS |
| 1867 | ACAX | AlliedSignal Inc. | added 1/99; eliminated 7/2000 | | NRHS |
| 1868 | ACAX | Honeywell International, Inc. | added 7/2000; 7/2000 | | NRHS |
| 1869 | ACAX | *ALUMINUM COMPANY OF AMERICA | | | PWRC |
| 1870 | ACAX | *ALLIED SIGNAL [ALLIED CHEMICAL DIV OF CANADA] (ALLIED CORPORATION) | | | PWRC |
| 1871 | ACAX | +HONEYWELL INTERNATIONAL, INC. | | | PWRC |
| 1872 | ACAX | Aluminum of America (Alcoa) | | | RSRV |
| 1873 | ACAX | HONEYWELL INTERNATIONAL INC | | | SCAC4 |
| 1874 | ACAY | ACADEMY AIR CARGO INC | | | SCAC3 |
| 1875 | ACB | African Cargo Services Limited | Callsign: Africargo, | EAK | AVCODES |
| 1876 | ACB | Air Business Contact A.B.C. | Callsign: Air Contact, | F | AVCODES |
| 1877 | ACB | Air Continental Africa | Callsign: Airconti, | G | AVCODES |
| 1878 | ACB | Achenseebahn | | A | TRAFFIC |
| 1879 | ACBA | ARABI CAB CO INC | | | SCAC3 |
| 1880 | ACBB | ADAM CAB INC | | | SCAC3 |
| 1881 | ACBB | A & C TRANSPORT | | | SCAC4 |
| 1882 | ACBC | ABLE CHARTER BUS COMPANY | | | SCAC3 |
| 1883 | ACBC | A&C Bus Corp | | USA | TRAFFIC |
| 1884 | ACBF | AR TRANSPORT | | | SCAC3 |
| 1885 | ACBJ | AIM CARIBBEAN EXPRESS | | | SCAC3 |
| 1886 | ACBK | ACADIA TRUCKING & BROKERAGE LTD | | | SCAC3 |
| 1887 | ACBL | American Commercial Barge Lines, Inc. (American Commercial Barge Line Division) | 1/1975-7/2005 | | NAKINA |
| 1888 | ACBL | American Commercial Barge Lines, Inc. (American Commercial Barge Line Division) | 1/75-1/80 | | NRHS |
| 1889 | ACBL | American Commercial Barge Lines, Inc. | Jan-94 | | NRHS |
| 1890 | ACBL | American Commercial Barge Lines, Inc. (American Commercial Barge Line Division) | Jul-00 | | NRHS |
| 1891 | ACBL | AMERICAN COMMERCIAL BARGE LINES, INC. | | | PWRC |
| 1892 | ACBL | American Commercial Barge Lines | | | RSRV |
| 1893 | ACBL | AMERICAN COMMERICAL BARGE LINE COMP | | | SCAC3 |
| 1894 | ACBL | ATLANTIC CARIBBEAN LINE INC | | | SCAC4 |
| 1895 | ACBM | ATLANTIC COAST TRANSPORTATION INC | | | SCAC3 |
| 1896 | ACBM | AUTOTRANSPORTES DE CARGA BALSA S A | | | SCAC4 |
| 1897 | ACBN | ACTION BONDED MESSENGER & DELIVERY | | | SCAC3 |
| 1898 | ACBN | ACTION TRANSPORT INC | | | SCAC4 |
| 1899 | ACBO | ACCO BABCOCK INC | | | SCAC3 |
| 1900 | ACBP | AC-BERWICK TRUCKING CORPORATION | | | SCAC3 |
