Witheld numbers and unknown numbers what is the difference?

Question

iv got caller number display on my landline phone is there a difference between witheld or unknown .i no its a silly question .i have the callersdisplay on for a reason ...anybody thanks xx

Answer 1

Not a silly question Emma, as a lot of people do not understand the difference.  

In the U.K. system, even when you place a call and use 141 your number is sent all the way to the destination exchange, but a little "flag" is sent too telling that exchange not to allow the called person to see your number.  

"Withheld" on your caller ID means that the number was received at the telephone exchange, but the caller deliberately chose to block his number from being sent to you.    That could be EITHER because he dialed 141 first to withhold the number for the one call, OR because he has his line set to withhold by default for all calls (and can then release his number for a single call by dialling 1470 first).  

"Unavailable" means that the calling number has not been sent through to the exchange for some reason.   That can often happen with calls from overseas, from some call centers, from calling cards, and so on, or simply because there was a problem somewhere in the network and the calling number just didn't get passed forward properly.

The difference between these two conditions is also reflected in the message you get when you use 1471.  

Withheld = "The caller withheld their number."

Unavailable/unknown = "We do not have the caller's number"

Answer 2

Withheld is when the calling party had stopped the number being forwarded to you CLI.

Unknown is when the exchange cannot forward the number, often this is from a switchboard, or another service provider and the CLIP (Calling Line Identity Presentation) has not been forwarded for some reason.

Hope this helps?

Answer 3

With few words

any number from outside the UK is an unkown number and Bt is unable to get

Answer 4

not much withheld is they put 141 infront unknown is when they have set it for the num not to show up