I purchased a gophone about 7 years ago.  LG GT550GO  It is a ATT "gophone".  Bought from a retailer for cash, dont think I had to "register" anything.  Phone is archaic, I need to upgrade to another go phone.  I have an old iphone 4s laying around.  My question is can I pull the standard size sim card and cut it down to fit the micro sim card of the 4s?  I swant to keep the number and have a large number of contacts in the phone.  I could transfer contacts manually BUT want to keep the phone.  
Is ATT "prepaid" still anonymous as was the go phone??  
Basically I want the same number on a better phone, all on the down low.
Still Thirsty my friends

Seems to me these questions would be better asked at the ATT store rather than here on the TER forum.

Personally, I don't have a secret "hobby phone". I only have a cellphone with Tracfone service that I keep out in plain sight all the time. Since Tracfone numbers get recycled and end up on robocall lists it rings all the time and I simply ignore it if I'm not expecting a call. Everybody else in the house does the same thing. When I use it for hobbying I just clean up all the numbers and/or texts afterwards to make sure nobody sees them but nobody has ever even looked. In my opinion this is better than keeping a secret phone because if your secret phone gets found then you are truly busted.

They sell cutters for that. Worse case it doesn’t work. Then go to Best Buy get a new smart phone pay cash and go. You won’t be able to transfer the old number without registering. Start emailing your favors to tell them ur new number.