"1. Please ensure you have the right version of the iPhone (iPhone 5: Model A1429/iPhone 5C: Model A1507/iPhone 5s: Model A1457) and are 4G LTE compatible 2. Your SIM card needs to be 4G LTE compatible 3. Try to go to Settings -- Cellular – Cellular Data ON, Enable LTE ON 4. If that doesn’t work then go to Settings – General – Reset – Reset Network Settings (insert device lock code if required)"