My friend recently gave me his old iPhone 4. I can't activate it because I don't have a data plan (lame!). I cannot get my own plan because I'm not 18. If I get a prepaid smartphone plan, could I activate the iPhone 4 with it after?
Can you buy a prepaid plan for verizon then get an iPhone and activate it?
No, the iPhone is not eligible for prepaid plans.
You will have two separate telephone numbers. The iPhone is not qualified at this time to be a GoPhone. Unless Apple designs a budget phone to be a GoPhone, then it won't work at all.
The previous person that answered your question is incorrect. You can use an UNLOCKED iPhone on Straight Talk or T-Mobile prepaid, but you will need a micro sim card from T-Mobile or Straight Talk, T-Mobile offers micro sim cards from their site for 99 cents. Straight talk offers micro sim cards from the walmart.com site for 14.99. You will also need to buy the pre-paid minutes in order to activate your pre-paid account. I just did the very thing with an unlocked iPhone that I purchased through the Apple store and I'm currently using on T-Mobile.
BTW, T-Mobile has unlimited pre-paid plans starting at $30.00 and up; Straight talk has unlimited pre-paid plans starting at 45.00, but with the iPhone on Straight talk you need to tweek your MMS settings in order to get your texting & picture messaging to work appropriately. Also, I hear that Straight Talk puts a cap on the internet usage once you reach 2GB, T-Mobile, which I'm using doesn't have caps, but I can't hardly use my phone once inside a building, if that helps. Check out a few YouTube videos on those that are using iPhone on T-Mobile and/or Straight Talk before making your decision, especially check out videos on speed tests and how to get MMS working before making your decision on which carrier to use.