A reader, David asks,

“do all iphones go on the sprint network with straight talk or like like, ie tmobile uses tmobile, verizon verizon etc.”

Hi David,
Generally, you register your on the Straight Talk network on the network it compatible with. So if you have an ATT iPhone, you’d use the Straight Talk ATT-compatible network, a T-Mobile iPhone would use the Straight Talk T-Mobile-compatible network, a Verizon iPhone would use the Straight Talk Verizon-compatible network, and Sprint iPhone would use the Straight Talk Sprint-compatible network.

But its a bit more complicated than that. ATT and TMobile iPhones use GSM technology. You buy either a Straight Talk att-compatible or Straight Talk tmobile-compatible SIM. If your GSM iPhone is locked to the ATT or TMobile network, you can only use network your phone is locked to. If your phone is unlocked you can pick which network to use. All GSM iPhones can be used on at least one of the two networks.

Verizon and Sprint iPhones use CDMA technology. You need to check if your iPhone is eligible for use on Straight Talk by entering your phone’s MEID and zi p code into the Straight Talk web site. IF your phone is eligible, you can use your Sprint iPhone with the Straight Talk Sprint-compatible. Verizon iPhones will use Straight Talk’s Verizon-compatible network if they are eligible. Straight Talk does not say how they determine eligibility. We do know that it is a combination of the area you live in, your phone model, and your MEID.

Currently you can only activate Sprint and Verizon iPhone 4 and iPhone 4s models on the ST Verizon and Sprint networks. The iPhone 5, iPhone 5s, and iPhone 5c models can not be used. Most likely this is based on a business relationship between the companies.

Finally, while the Verizon iPhone 5, 5c, and 5s cannot be used on Straight Talk’s verizon network, they can be used with Straight Talk’s att or tmobile network.