I thought landline calls to BT 1571 (to see who called) were free but I have been charged 35p on my latest bill for a call to 1571. Is this something new or am I mistaken in believing calls to1571 are free?
1571 is the answering service, 1471 is to see who called and is free.
1571 is free to Digital Voice customers but I'm not so sure it's free if your phone line is still on copper
1571 is 35p from analogue lines but free from Digital Voice lines
Then they've charged you wrongly
I covered this the other day, the 35p is the charge for pressing to return the call as per the below line from the tariff guide
Call Return (1571) You can press '0' to return the call after you have listened to your voicemail message 35.0p