Show witheld number?

Question

I am receiving nusiance calls on my mobile from a witheld number, my mums number always comes up witheld so cant not answer it, i know there used to be a number you could dial before you dialed the phone number, so that if your number was witheld it would show to the person your calling, does anyone know what this number is, hope you get wot i mean,

Thanks

Sharon x*x

Answer 1

after you pressed 141 do you have to put the moble number with 0 at the beginnig or without thr 0???