An air conditioning system according to the present invention includes: a first air conditioner; a second air conditioner; a first operation terminal capable of operating the first air conditioner; a second operation terminal capable of operating the second air conditioner; and a portable terminal that receives, from the first operation terminal, first setting information including first information for operating the first air conditioner or the second air conditioner, and second information that is information on the first operation terminal or the second operation terminal, generates transmission information on the basis of the first setting information, and transmits the transmission information to the second operation terminal.