Why does my telephone seem to need four wires?

[Lucien Nunes]

I don't know which pinout is more common in the UK now, most of the time I'm looking at things like audio conferencing units where 3-4 is normal, rather than telephones. If the job needs anything other than RJ45 to RJ11 I end up making it on the spot.

 

[ackbarthestar]

Ditto, Just cut off the old RJ11 and recrimp....