All individuals entering Tibet must hold a passport valid for at least six months. If you are entering Tibet from China, your Chinese visa will be valid, though only travelers with tourist visas (not business, resident or student visas) are permitted. Entering Tibet from Nepal, either by friendship highway or by air requires a separate visa valid for Tibet from the Chinese embassy in Katmandu (30-60 day visas are the norm and it normally takes 2 week days to obtain it.). You may apply for a group visa from us (minimum of two people in a group and you must leave China with this person unless you can change the visa inside China).