VISA FREE TRANSITS

Actually, you are eligible for 144 hour visa free transit because 72 hours were replaced by more generous 144 hours years ago as far as Shanghai area is concerned.

You just need to have your passport and to printout of your hotel booking confirmation for at least the first overnight in Shanghai. Also, it is advisable to have your flight tickets printed out and at hand.

You will declare in London, at check-in, that you travel to Kuala Lumpur via Shanghai based on 144 hour visa free transit. After a short check, you will be allowed to board the plane. Upon your landing in Shanghai, you will first approach 144 hour visa free transit counter where you will present your hotel booking and your onward flight to KL. Again, after a short check, you will be allowed to exit the airport and to enjoy your time in Shanghai. Yes, you will also fill out a simple arrival/departure card for China on board of the Shanghai bound flight or upon your landing.

When you are done with your stay in Shanghai, you will just proceed to your flight for KL... I would say, very simple...