Last night we received a nuisance call at 4.35am supposedly from the NHS telling us of a family breavement. The family member had died over 50 years ago so it was an obvious hoax. The number was withheld - are BT able to trace the number from which the call was made?
that is very unlikely did you report it to the police albeit I doubt they will do much if only one call.
In answer to your question " are BT able to trace the number from which the call was made?"
Will they trace it - probably not on the basis of one call unless they are asked to by the police.