Flying to Shenzhen from London

Only for them entering via some specific land borders (IIRC not available at Futian or Shenzhen Bay) or the Shekou ferry terminal.

I will just add that the alternative option is to use 144 hour visa free transit that will allow your colleagues to fly in and out of Shenzhen. To be eligible they have to do the following:

- Have an itinerary London - Shenzhen - Hong Kong
- They have to arrive in Shenzhen by direct, nonstop flight from London
- They will have to book a ferry ticket from Shenzhen Shekou port to Hong Kong Macau ferry terminal
- When they book ferry tickets from Shekou to Hong Kong through CKS - Chu Kong Passenger Transport website, they will receive an e-confirmation that they will have to print out and bring them with themselves as a proof for 144 hour visa free transit
- When the time comes, they will take a ferry to Hong Kong, but if they do not intend to remain there, they can return by the first available ferry back to Shekou where they will obtain a Shenzhen VOAs. Please, have in mind that the opening hours for Shekou Shenzhen VOA are: 9:00 - 13:00 & 14:30 - 17:00
- They can remain in Shenzhen another 5 days and after that they can depart from Shenzhen directly to London

Please, have in mind the following:

- Keep in mind that the interval between the scheduled landing in Shenzhen and scheduled departure by ferry to Hong Kong has to be at least 25 hours in order to be eligible for 144 hour visa free transit
- The flights to and from Shenzhen are not allowed to have any additional landing of any kind within mainland China
- Your colleagues will pay different prices for a Shenzhen VOA:

- US - 956 CNY
- UK - 304 CNY
- France - 168 CNY