If you are a foreigner and you are in Chile for more than a month, you must register your cell phone.
Thus You can go to any existing national operator (WOM, Entel, Claro, Movistar) and ask to register your equipment. There is also the possibility to make this registration completely online, and our page has this option for you to enjoy the trip to Chile.
Registration requires certain documents, but if you are a foreigner, a passport will suffice.
One of the advantages of doing this completely online is that your phone will continue to work on national networks. Remember that if a month goes by, if you work with a local company you will not be able to occupy the national networks.
You can register your IMEI here:
REGISTER IMEI