How Do You Register An Existing Number To Orange Sim Card?

I Have Just Ordered A New Mobile Phone And Have Changed My Contract Type. I Want To Keep My Existing Number. Can I Register On My New Sim Card?How Do You Register An Existing Number To Orange Sim Card?
It depends on the carrier... most carriers in the US, you have to call and have them activate the new card with your number.How Do You Register An Existing Number To Orange Sim Card?
if u ring your network provider you should be able to register the number you want providing your are the holder of that number already!