My experience is that Apple keyboards remember what it was paired with. I found that out when I wanted to switch the BT keyboard to another of my Macs. It would not pair with the other Mac until I "disconnected" it from the first Mac. The instructions said you had to disconnect. You might be able to get around it by taking the batteries out for a while. Turing off the keyboard and then back on did not allow pairing with my other Mac.