the best way po is to call the hotline to check your options.
margo1022 , yes, hcescala is correct. But on the onset, if you just got your Perfect Plan, then I don't think you can change it now. Changing it would be tantamount to pre-termination since you have a contract. If you mean you are just approved and no delivery yet of the handsets, then you can change but you will have to undergo another approval process for the 5s. Your approved Perfect Plan will be cancelled then.