The answer depends upon the network you choose.
Yes! If you have an existing Sprint SIM card, activate today on our CDMAS network - no need to order a Red Pocket SIM!
No, if you are going to use the Red Pocket GSMA, GSMT or CDMA network. BUT, don't fret, your Red Pocket SIM card and shipping are completely free when you order your first month of service.
If you want to use the CDMAS network, but no longer have your Sprint SIM, you can order a free Red Pocket CDMAS SIM with your first month of service.