| 4001 | WRWK | Trinity Rail Management, Inc. | Jul-00 | | NRHS |
| 4002 | WRWK | (PW) PROVIDENCE & WORCESTER RAILROAD CO. [WARWICK RAILWAY] | | | PWRC |
| 4003 | WRWK | Warwick Railway (Providence and Worcester Railroad) | | | RSRV |
| 4004 | WRWL | WESTERN REFINING WHOLESALE INC | | | SCAC4 |
| 4005 | WRWR | Warwick Railway | Real: WR | USA | TRAFFIC |
| 4006 | WRWS | WASTE RECOVERY WEST INC | | | SCAC4 |
| 4007 | WRWX | Trinity Rail Management, Inc. | 7/2000-7/2005 | | NAKINA |
| 4008 | WRWX | TRINITY RAIL MANAGEMENT, INC. | | | PWRC |
| 4009 | WRWX | Trinity Rail Management | | | RSRV |
| 4010 | WRWX | TRINITY RAIL | | | SCAC4 |
| 4011 | WRX | Wolff Refrigerator Line (Charles Wolff Packing Co.) | 8/1920 | | NAKINA |
| 4012 | WRX | Western Refrigerator Line Co. | 7/1935-4/1970; eliminated 1/1973 | | NAKINA |
| 4013 | WRX | Western Refrigerator Line Co. Terminal | added 1/1973; 1/1975-1/1980; eliminated 10/1990; 1/1994-7/2005 (not listed) | | NAKINA |
| 4014 | WRX | Western Refrigerator Line Co. | 4/38-4/70 | | NRHS |
| 4015 | WRX | Western Refrigerator Line Co. Terminal | 1/75-1/80; eliminated 10/90; 1/94-7/2000 | | NRHS |
| 4016 | WRX | *CHARLES WOLFF PACKING CO. [WOLFF REFRIGERATOR LINE] | | | PWRC |
| 4017 | WRX | +WESTERN REFRIGERATOR LINE COMPANY TERMINAL | | | PWRC |
| 4018 | WRX | Western Refrigerator Line | | | RSRV |
| 4019 | WRX | Western Refrigerator Line | | USA | TRAFFIC |
| 4020 | WRXR | WIRE EXPRESS INC | | | SCAC4 |
| 4021 | WRXT | WAREX TERMINALS CORP | | | SCAC4 |
| 4022 | WRXU | WEATHERHAVEN GLOBAL RESOURCES LTD | | CDN | BIC |
| 4023 | WRXU | Weatherhaven Global Resources | | | RSRV |
| 4024 | WRY | Waterloo Ry. Co. | 1/1994-7/2005 | | NAKINA |
| 4025 | WRY | Waterloo Ry. Co. | 1/94-7/2000 | | NRHS |
| 4026 | WRY | WATERLOO RAILWAY COMPANY | | | PWRC |
| 4027 | WRY | Waterloo Railway | | | RSRV |
| 4028 | WRY | WATERLOO RAILWAY COMPANY | | | SCAC4 |
| 4029 | WRYM | Whippany Railway Museum | | USA | TRAFFIC |
| 4030 | WS | Westjet Airlines Ltd. | ICAO: WJA, Callsign: Westjet, IATA Prefix: 838, Name changed to Westjet | CDN | AVCODES |
| 4031 | WS | African International Airways | ICAO: AIN, Callsign: Fly Cargo, IATA Prefix: 648, Founded in 1985. Ceased operations in 2008. Designator WS recalled by IATA | ZA | AVCODES |
| 4032 | WS | Schreiner Airways B.V. | ICAO: SCH, Callsign: Schreiner, Designator WS recalled by IATA | NL | AVCODES |
| 4033 | WS | Caraibes Air Transport | ICAO: ISB, Callsign: Island Bird, Designator WS recalled by IATA | GP | AVCODES |
| 4034 | WS | Westjet | ICAO: WJA, Callsign: Westjet, IATA Prefix: 838, Name changed from Westjet Airlines Ltd. | CDN | AVCODES |
| 4035 | WS | Wiltshire School of Flying LTd. | Callsign: Aerowilt, | GB | AVCODES |
| 4036 | WS | Ware Shoals R.R. Co. | 1/1975-1/1980; eliminated 1/1985 | | NAKINA |
| 4037 | WS | Walkersville Southern R.R. | 1/1994-7/2005 | | NAKINA |
| 4038 | WS | Ware Shoals R.R. Co. | 1/75-1/80; eliminated 1/85 | | NRHS |
| 4039 | WS | Walkersville Southern R.R. | 1/94-7/2000 | | NRHS |
| 4040 | WS | *WARE SHOALS RAILROAD | | | PWRC |
| 4041 | WS | +WALKERSVILLE SOUTHERN RAILROAD | | | PWRC |
| 4042 | WS | Ware Shoals Railroad | | | RSRV |
| 4043 | WS | WALKERVILLE SOUTHERN RAILROAD INC | | | SCAC4 |
| 4044 | WS | Sebastian Wetzel | | DE | VKM |
| 4045 | WSA | Westates Airlines | Callsign: Westates, | USA | AVCODES |
| 4046 | WSA | Westgates Airlines | | | ICAO1 |
| 4047 | WSAC | WESTERN DEDICATED LP | | | SCAC4 |
| 4048 | WSAG | WESTERN SHIPPING PTE LTD | | | SCAC4 |
| 4049 | WSAJ | WESTERN STAR TRANSPORTATION | | | SCAC4 |
| 4050 | WSAL | WESTERN SALES INC | | | SCAC4 |
| 4051 | WSAM | WESTERN SHIPPING AMERICA INC | | | SCAC4 |
| 4052 | WSAN | WSA LINES (INTL) LTD | | | SCAC4 |
| 4053 | WSAO | WHITE, S A OIL CO INC | | | SCAC4 |
| 4054 | WSAQ | WEICHENG SEA & AIR LOGISTICS LTD | | | SCAC4 |
| 4055 | WSAR | WERTMAN, S A TRUCKING | | | SCAC4 |
| 4056 | WSAS | WASHINGTON & SONS CORPORATION | | | SCAC4 |
| 4057 | WSAT | WIL-TRANS | | | SCAC4 |
| 4058 | WSAW | WILSON LAKE INC | | | SCAC4 |
| 4059 | WSAY | WSA TRUCKING CO | | | SCAC1 |
| 4060 | WSAY | WSA TRUCKING CO | | | SCAC4 |
| 4061 | WSB | West Side Belt R.R. Co. (Pittsburgh & West Virgina Ry.) | 8/1920-7/1936 | | NAKINA |
| 4062 | WSB | PITTSBURGH & WEST VIRGINIA RWY. [WEST SIDE BELT RAILROAD CO.] | | | PWRC |
| 4063 | WSB | Wynental- und Suhrentalbahn | | CH | TRAFFIC |
| 4064 | WSB | Wynental- und Suhrentalbahn (WSB) | | CH | VKM |
| 4065 | WSBA | WAGONSERVICE travel, ltd | | SK | VKM |
| 4066 | WSBB | W S BADCOCK CORP | | | SCAC4 |
| 4067 | WSBD | WESTSIDE BUILDING SUPPLY | | | SCAC4 |
| 4068 | WSBE | WEST & SONS TOWING INC | | | SCAC4 |
| 4069 | WSBI | WEISS, MITCHELL W | | | SCAC4 |
| 4070 | WSBK | W & S TRUCKING INC | | | SCAC4 |
| 4071 | WSBQ | WISCONSIN REFRIGERATED EXPRESS INC | | | SCAC4 |
| 4072 | WSBT | WESTFALL TRUCKING INC | | | SCAC4 |
| 4073 | WSBY | WESTBY TRUCKING | | | SCAC4 |
| 4074 | WSC | Gatwick Air Taxis Ltd. | Callsign: Gatwick Air, | GB | AVCODES |
| 4075 | WSC | Westair Cargo Airlines | Callsign: Westcar, | CI | AVCODES |
| 4076 | WSC | WESTERN STOCKYARDS CORP. | | | PWRC |
| 4077 | WSC | WASHINGTON CHARTERS | | | SCAC4 |
| 4078 | WSCC | WATERMAN STEAMSHIP CORP OF CALIF. | | | PWRC |
| 4079 | WSCC | WESTGATE TRANSPORTATION COMPANY | | | SCAC4 |
| 4080 | WSCE | WES STOR CONTAINER & TRANSPORTATION | | | SCAC4 |
| 4081 | WSCG | WISE TRUCKING | | | SCAC4 |
| 4082 | WSCH | WISCHMEIE | | | SCAC4 |
| 4083 | WSCI | WRIGHT STUFF COMPANY LLC, THE | | | SCAC4 |
| 4084 | WSCJ | WELTON SHIPPING CO INC | | | SCAC4 |
| 4085 | WSCK | WESMAR STEEL CORPORATION | | | SCAC4 |
| 4086 | WSCL | WATERFRONT SHIPPING COMPANY LIMITED | | | SCAC4 |
| 4087 | WSCP | WESTONE COMPANY, THE | | | SCAC4 |
| 4088 | WSCQ | WCI | | | SCAC4 |
| 4089 | WSCS | WILLIS CONSTRUCTION CO INC | | | SCAC4 |
| 4090 | WSCU | CARU CONTAINERS BV | | NL | BIC |
| 4091 | WSCU | CONTAINER ASSOCIATION ROTTERDAM BV- | | | SCAC4 |
| 4092 | WSCV | WEST SERVICE CENTER INC | | | SCAC4 |
| 4093 | WSCX | Willibald Schaefer Co. | 7/1937-4/1938; added 1/1968; 4/1970; eliminated 10/1972 | | NAKINA |
| 4094 | WSCX | Buffalo Brake Beam Co. | added 10/1980; eliminated 5/1983; 1/1994 (not listed) | | NAKINA |
| 4095 | WSCX | Consumers Energy Co. | added 4/2007 | | NAKINA |
| 4096 | WSCX | Willibald Schaefer Co. | 4/38; added 1/68; 4/70; eliminated 10/72 | | NRHS |
| 4097 | WSCX | Buffalo Brake Beam Co. | added 10/80; eliminated 5/83; 1/94 | | NRHS |
| 4098 | WSCX | *WILLIBALD SCHAEFER CO. | | | PWRC |
| 4099 | WSCX | *BUFFALO BRAKE BEAM CO. | | | PWRC |
| 4100 | WSCX | +CONSUMERS ENERGY CO. | | | PWRC |
