Does anybody know if I can add a third handset to my BT Synergy 4500 Twin.

I'm hoping the answer is not in the name!!

If yes, any ideas where I could purchase the additional handset from?

Eddie O'Reilly, June 2009

And Amazon

., June 2009

And a snip at only £9.99 from here...

http://www.telephonesonline.co.uk/_bt_syngery_4500.asp

You can have up to five handsets in total !!!

P, June 2009

They sell a 4500 - a Twin - a Trio & a Quad...

The user guide is here...
http://www.shop.bt.com/content/uni2/documentation/498m/025455.pdf

And page 81 says...

"If you have purchased a BT Synergy 4500 multiple pack
any additional handsets come pre-registered to the base.
If you have purchased an additional handset separately
you must register it to your BT Synergy 4500 base
before it can be used."

Peccavi, June 2009