| 1 | ZS | Azzzurra Air S.p.A. | ICAO: AZI, Callsign: Azzurra Air, IATA Prefix: 864, Ceased operations in March 2004. Designator ZS* reinstated by IATA | I | AVCODES |
| 2 | ZS | Hispaniola Airways, C. Por. A. | ICAO: HIS, Callsign: Hispaniola, Designator ZS recalled by IATA. | DOM | AVCODES |
| 3 | ZS | Kazaviaspas | ICAO: KZS, Callsign: Spakaz, Founded in 2003. Designator ZS recalled by IATA. | KZ | AVCODES |
| 4 | ZS | Sama Airways Ltd. | ICAO: SMY, Callsign: Najim, Suspended operations on 24 August 2010. | SA | AVCODES |
| 5 | ZS | Solinair Latelsko Podjetjet d.o.o. | ICAO: SOP, Callsign: Solinair, IATA Prefix: 265, IATA designator changed from SP*. | SLO | AVCODES |
| 6 | ZS | S-Bahn Zürich | | CH | TRAFFIC |
| 7 | ZS | Železnice Srbije | | RS | VKM |
| 8 | ZSAND | ZKM Sandomierz | | PL | TRAFFIC |
| 9 | ZSB | OHL ŽS a.s. | | CZ | VKM |
| 10 | ZSBA | Železničné stavebnictvo Bratislava a.s. | | SK | VKM |
| 11 | ZSBV | ZEALAND SHIPPING BV | | | SCAC4 |
| 12 | ZSC | Air Swazi Cargo (Pty) Ltd. | IATA: CW, Callsign: Swazi Cargo, ICAO designator changed to CWS | SD | AVCODES |
| 13 | ZSCL | STANDARD CHLORINE CHEMICAL CO. | | | PWRC |
| 14 | ZSCU | ZHANGJIAGANG SAEJIN CONTAINER COMPONENTS CO., LTD. | | PRC | BIC |
| 15 | ZSCW | ZANTE SHIPPING COMPANY | | | SCAC4 |
| 16 | ZSEU | ZHENG SUN ENGINEERING CO LTD | | | SCAC4 |
| 17 | ZSGW | ZHEJIANG SHIPPING GROUP ZHEHAI SHIP | | | SCAC4 |
| 18 | ZSI | Z&S International | | GB | TRAFFIC |
| 19 | ZSIC | ZEAGER & SONS INC | | | SCAC4 |
| 20 | ZSIU | SHAANXI ZHONGSHENG INUO NEW ENERGY EQUIPMENT CO. LTD. | | PRC | BIC |
| 21 | ZSKE | Železnicé stavby, a.s. Košice | | SK | VKM |
| 22 | ZSLC | ZP SERVICE LLC | | | SCAC4 |
| 23 | ZSMI | Z S & M INC | | | SCAC4 |
| 24 | ZSNP | ZSNP, a.s. | | SK | VKM |
| 25 | ZSNS | ZELLER & SONS ENT LTD | | | SCAC4 |
| 26 | ZSPZ | TRANSAMERICA LEASING, INC. | | | PWRC |
| 27 | ZSPZ | TAL International | | | RSRV |
| 28 | ZSPZ | TRANSAMERICA LEASING INC | | | SCAC4 |
| 29 | ZSR | Zeleznice Slovenskej Republiky | | SK | TRAFFIC |
| 30 | ZSR | Železnice Slovenskej Republiky | | SK | VKM |
| 31 | ZSRB | | Real: ZS | SR | TRAFFIC |
| 32 | ZSSF | ZERO SEVEN SIX TWO FOUR ZERO TWO (0 | | | SCAC4 |
| 33 | ZSSK | Zeleznièná Spoloènost' Slovensko, a.s. | | SK | TRAFFIC |
| 34 | ZSSK | Železničná Spoločnost\' Slovensko, a.s. | | SK | VKM |
| 35 | ZSSKC | Zeleznièná Spoloènost' Slovensko, a.s. | | SK | TRAFFIC |
| 36 | ZSSKC | Železničná Spoločnost\' Cargo Slovakia a.s. | | SK | VKM |
| 37 | ZSTA | ZWAAGSTRA TRUCKING LTD | | | SCAC4 |
| 38 | ZSTAV | Peter Hozák Želstav | | SK | VKM |
| 39 | ZSTC | Z'S TRANSPORT LLC | | | SCAC4 |
| 40 | ZSTD | ZELENAK STUDIOS | | | SCAC4 |
| 41 | ZSTL | ZST LOGISTICS INC | | | SCAC4 |
| 42 | ZSTO | ZOETEMAN, STUART | | | SCAC4 |
| 43 | ZSTP | Z'S TRANSPORT | | | SCAC4 |
| 44 | ZSTU | JSC SIBUR-TRANS | | RUS | BIC |
| 45 | ZSTU | JSC SIBUR-TRANS | | | SCAC4 |
| 46 | ZSU | Zsuzsivonat, Debrecen | Real: ZSEV | H | TRAFFIC |
| 47 | ZSYU | PETROCHINA NORTH CHINA CHEMICALS MARKETING COMPANY | | PRC | BIC |