find out who line rental is with

[aslco]

I've just moved into a new flat and have a live phone line. I have no idea who my line rental is with,but would like to know now as if their charge is ok I'll stick with them then get the broadband from whichever provider I like. The advantage of doing so is it will take a few days to setup rather than the 2 to 3 weeks it takes most companies to do the line switchover too. How do I go about finding who has the line rental?

 

[MissChief]

If you have a dial tone try 150 and see where you end up.

Any isp should have access to BT's Tags on line checker too.

 

[mattyfez]

You'll probably get a better overall deal if you take line and broadband from thesame provider.
The line rental is generally higher at around 14quid bit you get a discount on the broadband which brings the overall price more competetive.