Who is your mobile provider? Are you sure you have not altered the settings on your moble phone, so that your number is withheld?
Hi Keith.Vodafone is my mob provider,this trouble only started when we changed from sky to bt,i haven`t touched any settings on my mob,bt have tried allsorts but nothings been resolved.
If you ring other people on your mobile, do they see your mobile number displayed?
I cannot see how your landline could show your mobile number as withheld, if calls to your landline from other people get displayed correctly.
If you have a landline phone which has call blocking, maybe its rejecting your mobile number, try turning the call blocking off.