Best answer by Mohammed
I've merged your posts together as you've already created a topic relating to the same issue and posted elsewhere.
We're not able to transfer an existing iD Mobile number over to a new iD Mobile account.
You should be able to change your existing plan if you're on a SIM only or upgrade your existing plan to a handset contract.
If you email us onwe'll take a look at your account(s) and advise the best way for you to get the plan you're after whilst retaining your number.