Sprint has the new 3-in-1 BYOD SIM kit on sale for $0.00 w/free shipping via its website.
You will need this to use a BYOD device with Sprint or any Sprint network MVNO including Boost, Virgin Mobile, Ting, RingPlus, etc.
The universal kit works with the following devices:
Eligible devices include:
iPhone 6s Plus
iPhone 6 Plus
iPhone 5s (Verizon only)
iPhone 5c (Verizon only)
iPad Air 2
iPad Air (Verizon only)
iPad Mini 4
iPad Mini 3
iPad Mini 2 (Verizon only)
Nexus 6 (32 & 64 GB – black/white)
Nexus 5 (16 & 32 GB – black/white/red)
Nexus 5X (all versions)
Nexus 6P (all versions)
HTC One A9 (Sprint Version only)
Motorola X Pure Edition (16, 32 & 64 GB – all colors)
Eligible devices - Coming Soon:
Samsung Galaxy S7 Special Edition
Samsung Galaxy S7 edge Special Edition
Moto G4 Plus
You WILL need a credit card number to check out (because Sprint's POS system is dumb and doesn't believe that Sprint would really give anything away for free), but both the SIM and the shipping are free.
Normal price for the SIM kit is $9.99.