A:AnswerYou would need to buy a nano sim card from straight talk. When asked who your current service provider is just select AT&T or T-Mobile whichever picks up best in your area. The reason why I say this is because this phone only supports GSM not CDMA. Verizon and Sprint both use CDMA networks whereas AT&T and T-Mobile both use GSM and since this phone is only compatible on GSM networks that would be what you would need. Hope this helps. Also as an example if you purchase a AT&T sim card from straight talk that will be the towers in which your phone will be using for service or if you choose a T-Mobile sim that will be the towers used for service. Sorry for the long answer, I just thought I'd share what I didn't know for a long time on how these carriers work and the differences.
