VOA for UK citizen to Haikou

Sherif, you would be theoretically allowed to do that on VOA, but I will immediately discourage you to do that because the situation with Hainan VOA is almost completely unclear. It is the fact that Chinese authorities, after the introduction of 30 day visa free access for Hainan, are trying to diminish the weight of VOA and you will also notice that many agencies are doing exactly the same by mentioning VOA in very shy way. It is obvious that by such a discreet way, Chinese authorities are in the process of probably drastically changing the VOA or even to scrap this option entirely. So, I advise you to rely on 30 day visa free access where an agency has to be involved, but almost marginally and that same agency could be a good mediator in obtaining a Chinese visa while you are on Hainan, so you could proceed to Beijing or some other part of China. At least, this is my sincere opinion and a suggestion for your travel plans.

Sherif, you would be theoretically allowed to do that on VOA, but I will immediately discourage you to do that because the situation with Hainan VOA is almost completely unclear. It is the fact that Chinese authorities, after the introduction of 30 day visa free access for Hainan, are trying to diminish the weight of VOA and you will also notice that many agencies are doing exactly the same by mentioning VOA in very shy way. It is obvious that by such a discreet way, Chinese authorities are in the process of probably drastically changing the VOA or even to scrap this option entirely. So, I advise you to rely on 30 day visa free access where an agency has to be involved, but almost marginally and that same agency could be a good mediator in obtaining a Chinese visa while you are on Hainan, so you could proceed to Beijing or some other part of China. At least, this is my sincere opinion and a suggestion for your travel plans.

Thank you for your prompt reply and informative answer.
I was wondering if the 144-hr visa exemption transit option to go through Shanghai would be a valid option in this case (for example Seoul to Shanghai and Shanghai to another third country), and that it would allow me to stay in Shanghai for three days for example without needing a visa.
Thanks again

Sherif, please read the answer posted to Mo in the post just above yours.