Answered by Borut | Jul. 31, 2024 01:05
Yes, you are allowed to do that, but your total transit time in China should not exceed 24 hours even for just one minute. In other words, your journey will be covered by 24 hour visa free transit and you do not need any kind of visa.
You should prepare your travel by printing out your flight tickets because you will speed up the whole process. You will be asked in Istanbul at check-in to present your tickets because you will fly on two separate tickets and on unrelated airlines. After a short check into Timatic, you will be allowed to board the plane.
Upon landing in Shanghai, the first thing you will do is to approach 24/144 hour visa free transit counter where you will apply for a temporary entry permit in order to be allowed to exit the transit (airside) area. Here you will present your flight tickets and after a check, your permit will be granted and you will head to the immigration. Simply speaking, this is the only way how you could catch your onward flight to Japan because you will have to collect your luggage, formally enter China and then perform brand new check-in for your flight to Japan.
To conclude, you are allowed to do that because having two separate tickets and flying on separate airlines is fine as long as you stay within the rules of 24 hour visa free transit and that is your itinerary that is definitely eligible and the duration of stay in China that cannot exceed 24 hours.