For multi-dog households, you need one Fi Collar + one Fi Membership per dog to track each dog remotely.
Each Fi Collar operates as its own cellular device, so we need to establish one AT&T line per dog. This enables you to monitor each individual dog's whereabouts.
A membership gives you access to the full capabilities of your dog's Fi Collar - allowing Fi remote access to your dog's location and activity. The membership cost covers the GPS & LTE-M connection to your dog's Fi collar.
If you did not add a membership at checkout for a Series 2 Fi Collar, you can add one after you checked out by following the instructions here.