Review on 📞 AT&T SL80108 1.9GHz Extra Handset/Charger: Compatible with SL81108, SL81208, SL82118, and More! by Amber Marie

This phone requires a secret code to work. Not really. When it arrives, and after the battery has been inserted and charged for 10 minutes, the handset will simply say 'connect' when you place the handset on the base to register. I think it's because since it's a used phone it was once registered on a different basis. To de-register a handset from the old base, lift the handset from the base and dial *331734# on the handset, then press the menu key on the handset. The handset beeps. If you NOW place the handset on the base and follow the instructions to register, everything will work. The handset I received was immaculate - looked like it had never been used and had a new battery. After it turned out that you needed a secret code and had to deregister the phone, everything was fine.