If I have AT&T service currently, on a GSM iPhone... can I switch to Ting? My GF has it and loves it.
Not threadjacking I swears it! Just thought I'd ask while people were mentioning it...
AT&T & T-Mobile (and their MVNOs such as Airvoice, P'tel, Consumer Cellular) = GSM network and phones
Verizon & Sprint (and their MVNOs such as Ting, Page Plus, EcoMobile) = CDMA network and phones
CDMA and GSM are not compatible networks.
Things get murkier going into 4G LTE bands, but for the sake of simplicity and argument, you can't take GSM phones to CDMA providers. You have to buy new handsets to make the transition. Sometimes you can take CDMA phones that support 4G LTE (or are CDMA+GSM world phones) to GSM providers, but not always and not reliably.
The cheapest MVNO migration is to usually stick with an MVNO that uses the same network you were on in the first place as then you can just switch SIM cards or migrate carriers. There are exceptions to this rule as with everything, but that's where the value of the guide comes in.