How Can I Change Region Settings In iTunes? Here's The Answer.
In order for iTunes to fully change over to make purchases, you have to change the billing address to make that country. By that also means your credit card has to match that billing address too. You can get a gift card or prepaid card from that region to make it work also. If you have no credit card on file it should let you make free purchases after changing the billing address. One thing to note is that any apps or purchases from the other country code may not update or work if they are country specific. From what I can read, the phone number doesn’t matter so much as the billing address.