| 1901 | TCOZ | TERMINAL CONSOLIDATION COMPANY | | | SCAC4 |
| 1902 | TCP | Transcorp Airways | Callsign: Transcorp, | GB | AVCODES |
| 1903 | TCP | Transcorp Airways | | | ICAO1 |
| 1904 | TCP | TRANSCO CORPORATION | | | PWRC |
| 1905 | TCPA | TRANSPORTATION CORPORATION OF AMERI | | | SCAC3 |
| 1906 | TCPA | TRANSPORTES CANTU | | | SCAC4 |
| 1907 | TCPB | TRI-CAMPBELL LLC | | | SCAC4 |
| 1908 | TCPC | TARMAC TRANSPORTATION INC | | | SCAC3 |
| 1909 | TCPD | TRI-CITY PARCEL DELIVERY SERVICE | | | SCAC3 |
| 1910 | TCPE | TRI-COUNTY PETROLEUM INC | | | SCAC4 |
| 1911 | TCPG | TOWN & COUNTRY PKG EXPRESS | | | SCAC3 |
| 1912 | TCPH | T C PETROLEUM | | | SCAC4 |
| 1913 | TCPI | TARA CORP INDUSTRIES | | | SCAC3 |
| 1914 | TCPI | TRANSPORT CLAUDEL PELLETIER INC | | | SCAC4 |
| 1915 | TCPK | TRISTATE CRATING & PALLET CO INC | | | SCAC4 |
| 1916 | TCPL | TRANSPORTATION CONCEPTS LIMITED INC | | | SCAC3 |
| 1917 | TCPM | TRIMAC DRY BULK GROUP INC | | | SCAC4 |
| 1918 | TCPN | TCP TRANSPORTATION INC | | | SCAC4 |
| 1919 | TCPO | TRICO TRANSPORTATION | | | SCAC4 |
| 1920 | TCPP | TORCELLO SHIPPING CORPORATION, PIRA | | | SCAC3 |
| 1921 | TCPQ | TRANSPORT CPM | | | SCAC4 |
| 1922 | TCPS | TWIN CITY PASSENGER SERVICE | | | SCAC3 |
| 1923 | TCPT | TRANSPORT CONCEPTS INC | | | SCAC3 |
| 1924 | TCPT | TERLECKI EQUIPMENT | | | SCAC4 |
| 1925 | TCPV | T L CAMP TRAILER SALES CO | | | SCAC4 |
| 1926 | TCPW | TEAM CAMPBELL LOGISTICS PACIFIC LLC | | | SCAC4 |
| 1927 | TCPX | Taylor-Colquitt Co. | 1/1941-7/1954 | | NAKINA |
| 1928 | TCPX | Shippers' Car Line Corp. | eliminated 7/1954 | | NAKINA |
| 1929 | TCPX | Taylor-Colquitt Co. | 10/1957 | | NAKINA |
| 1930 | TCPX | Transport Capital | added 10/2000; eliminated 4/2001 | | NAKINA |
| 1931 | TCPX | Transport Capital Rail Partners, L.L.C. | added 4/2001; 7/2005; eliminated 1/2006 | | NAKINA |
| 1932 | TCPX | Trinity Industries Leasing Co. | added 1/2006 | | NAKINA |
| 1933 | TCPX | Taylor-Colquitt Co. | 1/52-10/57 | | NRHS |
| 1934 | TCPX | Transport Capital | added 10/2000; eliminated 4/2001 | | NRHS |
| 1935 | TCPX | Transport Capital Rail Partners, L.L.C. | added 4/2001 | | NRHS |
| 1936 | TCPX | *TAYLOR-COLQUITT CO. (SHIPPERS' CAR LINE CORP.) | | | PWRC |
| 1937 | TCPX | +TRINITY INDUSTRIES LEASING CO. [TRANSPORT CAPITAL RAIL PARTNERS, LLC] | | | PWRC |
| 1938 | TCPX | Transport Capital Rail Partners | | | RSRV |
| 1939 | TCPX | TRINITY INDUSTRIES LEASING COMPANY | | | SCAC4 |
| 1940 | TCPY | T COMPANY | | | SCAC3 |
| 1941 | TCPZ | (REAZ) TRANSAMERICA LEASING, INC. | | | PWRC |
| 1942 | TCPZ | TAL International | | | RSRV |
| 1943 | TCPZ | TRANSAMERICA LEASING INC | | | SCAC4 |
| 1944 | TCQ | Amber Aviation San Marino S.r.l. | Callsign: Amsan, | RSM | AVCODES |
| 1945 | TCQC | TRANSPRO CONTRACT CARRIERS INC | | | SCAC4 |
| 1946 | TCQF | TRUCKCRAFT CORPORATION | | | SCAC4 |
| 1947 | TCQG | T & C TRUCKING LLC | | | SCAC4 |
| 1948 | TCQI | TCA S R L | | | SCAC3 |
| 1949 | TCQL | TRICLOR LIMITED | | | SCAC3 |
| 1950 | TCQM | TRANSPORTES CAL-MAR | | | SCAC4 |
| 1951 | TCQN | TC INC | | | SCAC4 |
| 1952 | TCQO | TRANCO LOGISTICS LLC | | | SCAC4 |
| 1953 | TCQQ | TRANSPORTES CADI | | | SCAC4 |
| 1954 | TCQT | TATCAN TRUCKING INC | | | SCAC3 |
| 1955 | TCQU | Transport Canada | | | RSRV |
| 1956 | TCQX | Thrall Car Manufacturing Co. | added 4/2000; 7/2000; eliminated 1/2002 | | NAKINA |
| 1957 | TCQX | Trinity Rail Management, Inc. | added 4/2002; 7/2005 | | NAKINA |
| 1958 | TCQX | Thrall Car Manufacturing Co. | added 4/2000; 7/2000 | | NRHS |
| 1959 | TCQX | TRINITY RAIL MANAGEMENT, INC. [THRALL CAR MANUFACTURING CO.] | | | PWRC |
| 1960 | TCQX | Trinity Rail Management | | | RSRV |
| 1961 | TCQX | TRINITY RAIL MANAGEMENT | | | SCAC4 |
| 1962 | TCR | Laneas Aereas Trans Costa Rica, S.A. | Callsign: Ticos, | CR | AVCODES |
| 1963 | TCR | Lanaes Aereas Trans Costa Rica | | | ICAO1 |
| 1964 | TCRB | TRANS CARIBE EXPRESS SHIPPERS INC | | | SCAC4 |
| 1965 | TCRC | TRACTOR EIGHTY FOUR FIFTY SIX (8456 | | | SCAC3 |
| 1966 | TCRE | TACOMA RECYCLING CO INC | | | SCAC4 |
| 1967 | TCRF | TREASURE COAST REFRIGERATED TRANSPORT | | | SCAC3 |
| 1968 | TCRF | TREASURE COAST REFRIGERATED TRANSPO | | | SCAC4 |
| 1969 | TCRG | TIDEWATER CRANE & RIGGING COMPANY | | | SCAC3 |
| 1970 | TCRI | TRI-CITY RECYCLING INC | | | SCAC3 |
| 1971 | TCRK | TOM-CAT TRUCKING | | | SCAC3 |
| 1972 | TCRL | TRANSPORT CRISBEL LTD | | | SCAC3 |
| 1973 | TCRM | T-CAR CORPORATION OF MICHIGAN | | | SCAC4 |
| 1974 | TCRM | Transport en Commun de la Region Messine | City: Metz | F | TRAFFIC |
| 1975 | TCRN | TRANSPORT CARRIERS INC | | | SCAC3 |
| 1976 | TCRN | TERRAMAC CONTRACTING LTD | | | SCAC4 |
| 1977 | TCRO | TRI-COUNTY COMMUTER RAIL AUTHORITY {THREE COUNTY COMMUTER RAIL ORGANIZATION] | | | PWRC |
| 1978 | TCRP | TARR, C R INC | | | SCAC3 |
| 1979 | TCRR | TRANSPORT COURIER INC | | | SCAC3 |
| 1980 | TCRR | TRANSPORTES DE CARGA REFRIGERADA | | | SCAC4 |
| 1981 | TCRS | TUCOR SERVICES INC | | | SCAC3 |
| 1982 | TCRT | T C R TRANSPORT | | | SCAC3 |
| 1983 | TCRT | TRANS MAR DE CORTEZ EXPRESS S A | | | SCAC4 |
| 1984 | TCRU | TECHNO CONTAINER REPAIR LLC | | UAE | BIC |
| 1985 | TCRU | TCL - TANKCARGO CONTAINER LEASING S | | | SCAC3 |
| 1986 | TCRU | TCL - TANKCARGO CONTAINER LEASING S | | | SCAC4 |
| 1987 | TCRV | TAPIA CERVANTES, JOSE LUIS | | | SCAC4 |
| 1988 | TCRX | Trans-Crude Co. | 4/1947 | | NAKINA |
| 1989 | TCRX | *TRANS-CRUDE CO. | | | PWRC |
| 1990 | TCRX | *TENNESSEE CENTRAL RAILWAY MUSEUM | | | PWRC |
| 1991 | TCRX | *TIOGA CENTRAL RAIL EX. (NEW YORK) | | | PWRC |
| 1992 | TCRX | TEM COLE, INC. | | | SCAC3 |
| 1993 | TCRX | TENNESSEE CENTRAL RAILWAY MUSEUM | | | SCAC4 |
| 1994 | TCRY | Tri-City R.R. Co. | 7/2005 | | NAKINA |
| 1995 | TCRY | TRI-CITY RAILROAD CO. | | | PWRC |
| 1996 | TCRY | Tri-City Railroad | | | RSRV |
| 1997 | TCRY | TRI-CITY RAILROAD COMPANY | | | SCAC4 |
| 1998 | TCRY | Tri-City R.R. Co. | | USA | TRAFFIC |
| 1999 | TCRZ | TRI-CITY REGIONAL PORT DISTRICT | | | PWRC |
| 2000 | TCS | Transportes de Carga Aerea Especializada Y Servicios Aeronauticos | Callsign: Transcaesa, | MEX | AVCODES |
