OVERVIEW: Grab this SIM and you’ll be one step closer to award winning prepay with super low prices. Joining Skinny is as easy as taking your old SIM card out and sticking one of ours in. All you need to do is check below that your phone should be compatible with the network and that it's unlocked (this is especially important for devices purchased overseas). It should only take between 1-3 working days* to deliver your SIM to you.