Flying from London to Shenzhen

Part 1:

Gabbie, there are two important details to take into consideration:

1. Immigration procedures in China are accomplished at the very first landing in the same way as it is in Schengen area or in US. In other words, after your first landing, you will travel domestically and that is not allowed under 144 hour visa free transit scheme. So, you have to rule out 144 hour visa free transit option, but you can rely on 24 hour visa free transit scheme. This scheme allows you to have multiple stops within China, but it is important to understand that your entire transit time counting from your first scheduled landing, in your case in Changsha until your final departure from China, in your case from Shenzhen, cannot exceed 24 hours not even for a single minute.

2. In order to exit mainland China toward Hong Kong, you will need to buy a train ticket from Shenzhen to Hong Kong West Kowloon station in advance. You will print out that ticket and have that printout at hand ready to be presented to the relevant authorities as a proof of your real transit intention. Also, you will really have to take exactly that train.