Tibet is slightly more complicated when it comes to travel permits than elsewhere in China. An Alien Travel Permit (usually just called a ‘travel permit’) is granted by the PSB (Public Security Bureau) for travel to an area that is officially closed.
Tibet PSB will not issue travel permits to individuals and the travel permits are usually only obtainable through tour operators, for organized tours by four-wheel-drive car. A single permit is normally issued to all the people who are traveling together, the permit naming just one of them and stating how many others are accompanying him; the passports, or at least photocopies of passports and visas, of all persons traveling must be presented in order to obtain a permit.
If you want to do an overland tour from Yunnan, Sichuan or Xinjiang province to Tibet, your Entry Stamp to China is required to apply the PSB before your tour starts.
