Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
You can't get a nano-sim online for prepaid. Prepaid requires you to buy a SIM activation kit (it comes with an activation code). You will have to order a micro or regular sim online and setup your account once you receive the sim. Then you can either cut it down or go into a T-Mobile store for a nano-sim (but you will need an active account first).

Would this work? http://www.amazon.com/T-Mobile-NANO-CUSTOM-Prepaid-Activation/dp/B009G7AUQ2

So I get the phone in the mail with the sim I have already. I call Tmobile to setup an account. (I thought you can do it manually online?) Anywho, they are going to ask what type of account I want I'm sure, then they will tell me no because I don't have the correct SIM. Then I will go to a Tmobile store and ask for a nano sim?

Is it active once I call Tmobile to setup or does active mean having some sort of plan/mins on it?
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.