It is possible to enter Bolivia from Chile taking a tour from San Pedro de Atacama through the N.P. Eduardo Avaroa and the amazing Salar de Uyuni to Uyuni, or to Tupiza. The transfer from San Pedro to the Bolivian border is included in the tour.

Please be aware that there is a big difference in altitude with San Pedro de Atacama.
There is a chance that you will get high altitude disease, so make sure that you are acclimatised before you undertake the tour.
The Jeep has oxygen on board for in case of emergency.

Important notes:
Due to climate and road conditions, for all tours through the Salar de Uyuni routes may vary and can sometimes be changed without notice, reason for which details of the tours through the Salar de Uyuni are only for reference, and are not to be taken as an exact itinerary of what the tours implies.

For tours to and from San Pedro de Atacama, Chile, also is applicable: If due to climate and/or road conditions the border crossing between Bolivia/Chile at Hito Cajón is closed, the tour will be diverted to the border crossing at Ollagüe, if possible. This diversion brings extra costs with it that are not included in the tour and that have to be paid by the client on the spot.