Four pieces of information are necessary for overseas tourists traveling to Tibet, a valid passport, a valid visa, a Tibet Entry Permit (TTB Permit) and an Alien Travel Permit (PSB Permit). Those coming from Taiwan, Hong Kong SAR and Macau SAR must also carry these four documents. However, journalists and people that may be involved in political matters are not included in the above groups, for they must travel to Tibet under arrangements made by the Foreign Affairs Office of the Tibet government.
Generally speaking visas can be obtained from local China consulates in your native country. However, there are two exceptions: travelers from countries having a visa exemption agreement with Hong Kong do not need a visa and travelers coming to Lhasa from Katmandu have to get a visa from the Chinese Embassy in Kathmandu as regulated in an official memo between China and Nepal.
Overseas tourists are not allowed to visit Tibet by themselves and they must register with a licensed Chinese tour operator that will help them obtain a Tibet Entry Permit . Application for Tibet Entry Permit has to be delivered at least ten days prior to the entry date. Information submitted should include the traveler's full name, gender, date of birth, passport number, nationality and occupation. All should be listed exactly as on the passport. Passport and visa duplicates are necessary. A Tibet Entry Permit usually costs around 10 US D / per head if you contact with a tour agent in China.

One Tibet Entry Permit is issued for each tourist group and is held by the guide. No individual foreign tourist is allowed to carry it. That is to say that either your guide or your private car driver can hold the permit so as to let you have some free time at Lhasa. A service package normally includes transfers and guide.