| 2101 | SCZD | SUSTAITA CARGO SA DE CV | | | SCAC4 |
| 2102 | SCZE | SUN CARGO CONTAINER LINE LTD | | | SCAC4 |
| 2103 | SCZG | SOTO CRUZ, CONSUELO GUADALUPE | | | SCAC4 |
| 2104 | SCZI | SCALZO UTILITIES INC | | | SCAC4 |
| 2105 | SCZL | SCHAETZEL TRUCKING COMPANY INC | | | SCAC4 |
| 2106 | SCZM | SANCHEZ, ISMAEL | | | SCAC4 |
| 2107 | SCZN | SCHWARZ OIL TRUCKING | | | SCAC4 |
| 2108 | SCZP | S & R CORPORATION | | | SCAC4 |
| 2109 | SCZR | SAUTTER CRANE RENTAL INC | | | SCAC4 |
| 2110 | SCZT | SANTA CRUZ NUTRITIONALS | | | SCAC4 |
| 2111 | SCZU | SEACO SRL | | BDS | BIC |
| 2112 | SCZU | YORKSHIRE MARINE CONTAINERS | | | PWRC |
| 2113 | SCZU | Yorkshire Marine Containers (BNSF Railway) | | | RSRV |
| 2114 | SCZU | SEA CONTAINERS LTD | | | SCAC4 |
| 2115 | SD | Sudan Airways Co. Ltd. | ICAO: SUD, Callsign: Sudanair, IATA Prefix: 200, | SUD | AVCODES |
| 2116 | SD | Servicerail Deutschland GmbH | | DE | VKM |
| 2117 | SDA | St. Andrews Airways Ltd. | Callsign: Saint Andrews, | CDN | AVCODES |
| 2118 | SDA | Sogdiana | | TJ | AVCODES |
| 2119 | SDA | Sounds Air Travel & Tourism Ltd. | IATA: S8, | NZ | AVCODES |
| 2120 | SDA | St. Andrews Airways | | | ICAO1 |
| 2121 | SDA | SAN DIEGO & ARIZONA RAILWAY | | | PWRC |
| 2122 | SDA | San Diego and Arizona Railway | | | RSRV |
| 2123 | SDA | San Diego & Arizona Railway | | USA | TRAFFIC |
| 2124 | SDAA | SELMA DISPOSAL & RECYCLING INC. | | | SCAC4 |
| 2125 | SDAC | SUSQUEHANNA ECONOMIC DEVELOPMENT ADMINISTRATIVE COUNCIL OF GOVERNMENT | | | PWRC |
| 2126 | SDAC | S & D FREIGHT SERVICE INC | | | SCAC4 |
| 2127 | SDAD | SANDMAN, DAVID | | | SCAC4 |
| 2128 | SDAE | San Diego and Arizona Eastern Ry. Co. | 4/1938-1/1975; eliminated 1/1980 | | NAKINA |
| 2129 | SDAE | San Diego and Arizona Eastern Ry. Co., Kyle Santa Rosa, Inc.—Operation-Over | added 1/1980; 1/1980; eliminated 4/1980; eliminated 10/1980 | | NAKINA |
| 2130 | SDAE | San Diego and Arizona Eastern Transportation Co. | added 10/1980 | | NAKINA |
| 2131 | SDAE | San Diego and Arizona Eastern Ry. Co. | 4/38-1/75; eliminated 1/80 | | NRHS |
| 2132 | SDAE | San Diego and Arizona Eastern Ry. Co., Kyle Santa Rosa, Inc.--Operation-Over | added 1/80; 1/80; eliminated 4/80; eliminated 10/80 | | NRHS |
| 2133 | SDAE | San Diego and Arizona Eastern Transportation Co. | added 10/80 | | NRHS |
| 2134 | SDAE | SAN DIEGO & ARIZONA EASTERN TRANSPORTATION CO. [SAN DIEGO & ARIZONA EASTERN RY] | | | PWRC |
| 2135 | SDAE | San Diego and Arizona Eastern Railway | | | RSRV |
| 2136 | SDAF | SAME DAY DELIVERY INC | | | SCAC4 |
| 2137 | SDAF | Sudan Air Force | | SUD | TRAFFIC |
| 2138 | SDAI | SDR TRUCKING LLC | | | SCAC4 |
| 2139 | SDAN | SWEET, DANA H TRUCKING INC | | | SCAC4 |
| 2140 | SDAP | SOUTHWEST DEDICATED TRANSPORT LLC | | | SCAC4 |
| 2141 | SDAQ | S & D SHIPMANAGEMENT GMBH & CO KG | | | SCAC4 |
| 2142 | SDAT | STAR TRANSPORT, INC. | | | SCAC1 |
| 2143 | SDAT | STAR TRANSPORT INC | | | SCAC4 |
| 2144 | SDAW | SCHROEDER, DM TRUCKING | | | SCAC4 |
| 2145 | SDAX | Pacific Southwest Railway Museum Association d/b/a San Diego & Arizona Ry. | 7/2005 (not listed) | | NAKINA |
| 2146 | SDAX | PACIFIC SOUTHWEST RAILWAY MUSEUM ASSOC. d/b/a SAN DIEGO & ARIZONA RWY | | | PWRC |
| 2147 | SDAX | SAN DIEGO & ARIZONA RAILWAY (PACIFI | | | SCAC4 |
| 2148 | SDAY | SAME DAY TRANSPORTATION INC | | | SCAC4 |
| 2149 | SDB | Sukhoi Design Bureau Company | Callsign: Su-craft, | RUS | AVCODES |
| 2150 | SDB | Sukhoi Design Bureau Company | | | ICAO1 |
| 2151 | SDBB | Somerset Terminal R.R. Co. | 7/2005 | | NAKINA |
| 2152 | SDBB | SOMERSET TERMINAL RAILROAD CO. | | | PWRC |
| 2153 | SDBB | Somerset Terminal Railroad | | | RSRV |
| 2154 | SDBB | SOMERSET TERMINAL RAILROAD CO | | | SCAC4 |
| 2155 | SDBC | STEUBER DISTRIBUTING CO | | | SCAC4 |
| 2156 | SDBD | SHIPPING & DISTRIBUTION LTD | | | SCAC4 |
| 2157 | SDBH | SDB TRANSPORTATION INC | | | SCAC4 |
| 2158 | SDBJ | SAVINO DEL BENE USA INC | | | SCAC4 |
| 2159 | SDBL | SUDBURY LOGISTICS | | | SCAC4 |
| 2160 | SDBO | SANDIA DISTRIBUTORS INC | | | SCAC4 |
| 2161 | SDBP | SANDOVAL, DANIEL TRUCKING INC | | | SCAC4 |
| 2162 | SDBQ | SCHEPPS DAIRY | | | SCAC4 |
| 2163 | SDC | Sunrise Airlines | Callsign: Sundance, | USA | AVCODES |
| 2164 | SDC | Sunrise Airlines | | | ICAO1 |
| 2165 | SDCA | SOLUCIONES DE CARGA INTERNACIONAL S | | | SCAC4 |
| 2166 | SDCF | SUNDANCE FUELS INC | | | SCAC4 |
| 2167 | SDCG | S & D CARTAGE COMPANY | | | SCAC4 |
| 2168 | SDCH | S P R DE R I EL CHICURAL | | | SCAC4 |
| 2169 | SDCI | SHER-WOOD HOCKEY INC | | | SCAC4 |
| 2170 | SDCJ | SCHULTZ, D & CO LLC | | | SCAC4 |
| 2171 | SDCK | SANDRIC TRUCKING INC | | | SCAC4 |
| 2172 | SDCM | SPENCER, J J TRANSPORT II LP | | | SCAC4 |
| 2173 | SDCO | SOUND OIL COMPANY INC | | | SCAC4 |
| 2174 | SDCQ | SCOTT-DALE CARTAGE INC | | | SCAC4 |
| 2175 | SDCR | SAMEDAY W | | | SCAC4 |
| 2176 | SDCU | SC SADACHIT PRODCOM SRL | | RO | BIC |
| 2177 | SDCU | Southern California Edison | | | RSRV |
| 2178 | SDCV | STANDARD CONCRETE MATERIAL INC | | | SCAC4 |
| 2179 | SDCX | Standard Distilling & Distributing Co. | 8/1920 | | NAKINA |
| 2180 | SDCX | Southern Dyestuff Corp. | 1/1952-10/1957; eliminated 1/1958 | | NAKINA |
| 2181 | SDCX | Smith-Douglass Co., Inc. | added 7/1962; 7/1965; eliminated 10/1965 | | NAKINA |
| 2182 | SDCX | Smith-Douglass, a Division of the Borden Chemical Co. | added 10/1965; 10/1966; eliminated 10/1969 | | NAKINA |
| 2183 | SDCX | Smith-Douglass, a Division of Borden Chemical, Borden, Inc. | added 10/1969; 4/1970; eliminated 1/1972 | | NAKINA |
| 2184 | SDCX | Borden Chemical, Division of Borden, Inc. | added 1/1972; 1/1975-1/1980 | | NAKINA |
| 2185 | SDCX | AMAX Phosphate, Inc. | added 7/1981; eliminated 7/1983 | | NAKINA |
| 2186 | SDCX | AMAX Chemical Corp. | added 7/1983; eliminated 1/1988 | | NAKINA |
| 2187 | SDCX | Consolidated Minerals, Inc., Feed Supplement Division | added 1/1988; 1/1994-7/2005 | | NAKINA |
| 2188 | SDCX | Southern Dyestuff Corp. | 1/52-10/57; eliminated 1/58 | | NRHS |
| 2189 | SDCX | Smith-Douglass Co., Inc. | 7/65; eliminated 10/65 | | NRHS |
| 2190 | SDCX | Smith-Douglass, a Division of the Borden Chemical Co. | added 10/65; 10/66; eliminated 10/69 | | NRHS |
| 2191 | SDCX | Smith-Douglass, a Division of Borden Chemical, Borden, Inc. | added 10/69; 4/70; eliminated 1/72 | | NRHS |
| 2192 | SDCX | Borden Chemical, Division of Borden, Inc. | added 1/72; 1/75-1/80 | | NRHS |
| 2193 | SDCX | AMAX Phosphate, Inc. | added 7/81 | | NRHS |
| 2194 | SDCX | AMAX Chemical Corp. | eliminated 1/88 | | NRHS |
| 2195 | SDCX | Consolidated Minerals, Inc., Feed Supplement Division | added 1/88; 1/94-7/2000 | | NRHS |
| 2196 | SDCX | *STANDARD DISTILLING & DISTRIBUTING CO. | | | PWRC |
| 2197 | SDCX | *SOUTHERN DYESTUFF CORP. | | | PWRC |
| 2198 | SDCX | *BORDON CHEMICAL DIV. BORDON, INC. [SMITH-DOUGLAS CO. INC.] | | | PWRC |
| 2199 | SDCX | *RETIRED 04-26-94 ATP [AMAX CHEMICAL CORP.] | | | PWRC |
| 2200 | SDCX | +CONSOLIDATED MINERALS INC. FEED SUPPLEMENT DIV. | | | PWRC |
