Please be sure that you have covered the following tasks:
- Ensure iPhone is updated with the latest iOS (Settings – General – Software Update).
- Update SIM Unlocker with latest ICCID Code.
- Ensure iPhone is not blacklisted.
- Ensure iPhone is not iCloud lock bypassed via jailbreak.
- Ensure iPhone uses GSM technology (unlocker does NOT support CDMA technology).
- Ensure carrier SIM card is NOT from these carriers (they are not supported): Tracfone, Straight Talk, Total Wireless, Simple Mobile. (Unless iPhone is on “GSM -> GSM” and/or “CDMA -> GSM” technologies.
- Ensure chip is not scratched, bent or damaged in any way.
Unlock again using SIM Unlocker and be sure you aren’t doing these “CANNOT DO” tasks:
- DO NOT factory reset iPhone (will need to unlock again),
- DO NOT update iOS via iTunes, phone wired to PC (will need to unlock again).
- DO NOT change SIM cards too often (may need to unlock again).