A thermostat management system facilitates an automatic pairing of a thermostat with a thermostat communication account. The thermostat management system receives a public network address associated with a computer device on a private network accessing the thermostat management account. The system retrieves the thermostat metadata including a public network address associated with a registration of the thermostat with the thermostat management system. The public network address registered with the thermostat metadata is provided by a router on the private network and therefore should match the public network address used by computer devices on the private network. The thermostat management account is paired with the thermostat if the thermostat has the same public network address as the computer device accessing the thermostat management account. Pairing the thermostat management account to the thermostat allows the thermostat management account to communicate with the thermostat over the public network through the thermostat management system.