As long as the phone and service plan are the same you can do anything you want as far as buying a new phone or switching service plans.
biddie4ever, the answer is YES but only if you are currently using (just purchased) one of the UNLIMITED Plans.
This phone requires the use of the $45 Unlimited Plan (or the multiples of 90-, 180-, or 365-day blocks) or the $60 Unlimited International Plan. If you just purchased one of these plans, you can just transfer this new phone to the remaining time you have on your account. This phone will not work with the $30 Plan, however.
THEREFORE, if your current plan is the $30 Plan, then you will forfeit any remaining time that you might have left and will have to start a new Unlimited Plan from scratch. If this is the case, it will probably make more sense to wait and activate the new phone as close to your current "service end date" as possible so as not to waste the money on the $30 Plan you just purchased as Straight Talk does not give refunds on plans already purchased.
answered 5 months, 1 week ago