Hi, I work in Korea. I want to visit Shanghai for 72 hours before I go to back England.

Dear Sir/Madam,
I am a British citizen working in South Korea. I want to fly home to England. But, I would like to visit Shanghai for 72 hours before I fly back to England.

Can I buy 2 separate air-tickets e.g. a Korean Airlines ticket to Shanghai, and a British Airways ticket to England, and get a 72-hour transit? I am not sure if they will want a transit ticket from just one airline, or they can be different.

In short, I just want to take advantage of the 72-hour transit exemption to see Shanghai before I return to England.

Regards
Chris