The Shanghai–Kowloon through train was a train that ran between Hong Kong and Shanghai railway station in China, jointly operated by the MTR Corporation Limited of Hong Kong and China's national rail service (Shanghai Railway Bureau).

After 1 October 2003, passengers taking Z99B could not disembark at the stops listed above, as all travellers to Hong Kong from Shanghai clear Chinese immigration and customs at Shanghai station, and once they had done so they were considered to have left Mainland China and were no longer permitted to leave the train until their arrival at Hung Hom station.

The same rule also applied to northbound travellers (Z100B) who would clear Chinese immigration once they had arrived at Shanghai station.

[2] Due to the COVID-19 pandemic, services to Hong Kong have been suspended indefinitely since 30 January 2020.

After the resumption of train services was suspended due to COVID-19, this series of train services only retain the itinerary within mainland China (Shanghai-Guangzhou) and no longer operate the itinerary to Hong Kong.