Visa free transit eligible itinerary

David, unfortunately, your flight itinerary is not eligible for 144 hour visa free transit. Simply speaking, you are not allowed to have two mainland Chinese stops in a row. To be precise, your mainland Chinese stop has to have both immediate points, before and after in two different countries or eligible territories.

It is only 24 hour visa free transit that allows you to travel via China with more than one stop in a row.

To conclude, if you do not want to obtain a Chinese visa in advance, your imperative is to buy your ticket from Shanghai to Bangkok in order that your transit time in China, counting from your first scheduled landing (in your case in Beijing) until your last scheduled departure (in your case from Shanghai) remains shorter than 24 hours. In other words, your flight for Bangkok should depart within 24 hours in relation to the arrival of your flight in Beijing.

If you decide to use 24 hour visa free transit, you can use separate tickets and unrelated airlines. As far as the formalities are concerned, the first thing you will do upon your landing in Beijing will be to approach 24/144 hour visa free transit where you will apply for a temporary entry permit by presenting your flight tickets because your next flight will be a domestic one. After your permit is granted, you will proceed to the immigration and then to your flight to Shanghai and from there to your flight to Bangkok.