We need to sort out what type of Base you have and if your phone is a system handset.
If you have the base that also is a charging station, you cannot connect more phones to that base.
Also, if you have a MKI phone and this base, you probably need to upgrade the handset to a system handset. Done easily at a service center and may cost 30 euro. You can tell from the settings menu in you handset if its a system phone. If you have an "advanced settings" option you have a system handset. If not, you need the sw upgrade.
The correct base for your MKI handset, is:
http://www.beoworld.org/prod_details.asp?pid=1234
That will enable you to connect more handsets.
/Claes
_____________
Happy owner of: BV10, 2 x Beocom 2, Beocom 6000, Beocenter 2, Beolab 3, Beolab 2000, Beo4, Beolab 11
1:st prize winner Beoworld January Price Draw.