Tibet Travel Permit:
Tibet Travel Permit is foremost and compulsory for foreign passport holders to enter Tibet. It is issued by Tibet Tourism Bureau and is also called TTB permit. Without permit you can’t board a flight or train to Tibet or cross overland from Nepal.
According to policy of Tibet Tourism Bureau, traveler can’t apply the Tibet Travel Permit on their own. They have to book tour service from a certified agency, and let the agency apply the permit.
In order to apply for permit you have to send scanned copies of your valid passport and China Visa to your travel agency.
A valid Chinese visa is required to enter Tibet. If you are planning to arrive in Lhasa via mainland China, you would need to apply for your Chinese visa from the Chinese Embassy in your country.
On the other hand, if you are planning to fly to Lhasa via Kathmandu or go overland via Kerung or Simikot border, you would need to arrive in Kathmandu at least 2 to 6 days (if you want to apply for the minimum visa – normal charge) before your entry into Tibet.
Chinese Embassy in Kathmandu issues visas only on Mondays, Wednesdays & Fridays from 09:00 AM-11:00 AM.