Have the manager at each location set up the dot with their own phone number... simple as that. Share everyone's numbers with everyone else and your done. If someone moves on, the 50 dollar dot is replaceable without a sneeze... hell... even let them take it with them if they think it's a problem... but speaking from experience, I know you can reset the Dot to factory and unregister it and sever ties with it from your phone... So setting it up with a new manager is no issue if that occurs either...