If I change my phone number in May, but I am eligible for a new phone in late July, will that change my plan so that I won't be eligible for the new phone in May and have to wait another 2 years to upgrade? I don't want to wait until July to change my number, as I need to for business. Any help would be great thanks!!
Changing your number will not change your contract or affect your eligibility to upgrade in July.
When you do change the number though, make sure it takes effect at the beginning of your billing cycle, if possible, because your minutes will be prorated between the two numbers if you switch mid-cycle, and that could potentially result in overage charges.