How long will you study in China? If you will study in China for more than six months, you should apply a X-visa. The following documents are required:

1. Applicant's passport with blank pages and at least 6 months validity left before expiration.

2. A truly and completely filled application form affixed with one passport-sized photo.

3. An admission notice from the Chinese school is required.

4.X Visa applicant shall also provide an approved Foreign Student Visa Application Form (JW101 or JW202) issued by the Chinese authorized unit.

5.The applicant who will study in China for more than six months shall also provide a Physical Examination Certificate for Foreign Citizen ( the certificate must be provided by a designated hospital.)

Note: The holder of X Visa shall go through residential formalities in the local public security department within thirty days of entry into China.

Hello,

I have a British passport and at the moment I'm in Thailand and need to get a visa for China, do I need a letter of invitation or will flight details and a hotel booking be enough

For a Chinese tourist visa, you don't have to provide an invitation letter. Flights ticket and hotel reserve plus the basic required docoments(passport&application form) will be enough.