Just an FYI - I bought an unlocked S10+ through Best Buy, used the Sprint Bring Your Own SIM Kit that has the SIMOLW516TQ Part inside - popped the SIM Card in and works perfectly. You can buy the Sprint SIM Kit at Best Buy, even lists the part number on the back. NOTE: The Boost Mobile SIM Kit available at Best Buy DID NOT have the required part/SIM Card inside. Once the package is opened opened, it is not refundable. Was lucky to have incredibly knowledgeable Best Buy & Samsung Reps working with me to steer me straight. Hope this helps everyone!
Edwin1172, the SIM kit is a 4 in 1 and it cost $9.99 from Best Buy. I just bought one yesterday. The SIM card you need is SIM card D. It has the letter D in all black on it. That's SIMOLW516TQ.
Jordan, you have to go in to the store or just call first to confirm that they have it. It's not sold online through bestbuy.com
I don't know why, but when I searched online I couldn't find it. I went in to the store and they had it. Or you can just order the SIM from E-Bay for like $5. Just order the right one. Type the SIM card number into the search. https://www.ebay.com/p/Sprint-boost-virgin-Nano-4ff-SIM-Card-D-Simolw516tq-854798005262-iPhone-XS-XR...
You need SIMOLW516TQ It says SIM card D right on the back.