Tibet is a special land in China. If as a foreigner wants to travel to Tibet, you need to apply for the Tibet Travel Permit. If you go hiking on Kailash from mainland China, you will need your passport, Chinese Visa, and Tibet Travel Permit. If you start your Tibet trip from Nepal, you will need a China Group Visa, Tibet Travel Permit, and your passport.
Maybe I know something about Tibet Travel Permit because I went to Tibet for sometimes. If you decide to travel to Tibet, you should hold this permit. Tibet Travel Permit can only be applied by a local Tibetan travel agency. And you should send your passport, Chinese visa to the agency. Then they will help you apply for it.
As we all know that there's no direct flight to Tibet from other country except for Nepal. If you travel to Tibet from mainland China, you need to get a Tibet Travel Permit, China Visa and your passport. If you travel to Tibet from Nepal, you need to get a China Group Visa, TTP and your passport.
As one of the most sacred destination for many pilgrims and tourists, Mount Kailash attracts thousands of people every year from both home and abroad. Mount Kailash is located in Ngari which is in the frontier military-controlled area of Tibet, thus it is a little complicated for tourists to apply Tibet permits, including Tibet Travel Permit, Foreign affairs permit, Alien's Travel Permit and Military Permit. Of course, your passport and China Visa the prerequisite to apply for these permits.