No pun intended I've just received BT Call Sign on my line, so I can use my new HP OfficeJet 4215 as a fax.. I'm not sure its compatible with BT's tone/rings, as it fails to answer on all of its compatible distinctive rings? The OfficeJet can only recognise Double, Triple, and Double & Triple rings (as well as the standard ring). So, what do BT use.. A totally different ring I bet, huh....Just my luck.