How to find your mobile number on your sim even you don't have credit

Got a customer today who needs his mobile just for others to call him. He got a vodafone sim with no credit. How can we find the mobile number?

Having done a bit of googling, I found after u press * # 1000 #, it will pop up your phone number on screen.

more info for other secret code on vodafone

http://online.vodafone.co.uk/dispatch/Portal/appmanager/vodafone/wrp?_nfpb=true&_pageLabel=template12&pageID=OS_0034

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I shall add some more info about it on other networks later

O2 - check balance

Press * # 1 0 # then press send

Balance will then show on screen.

or Dial 4444 
choose option 2
choose option 2