How to format Apple's mobile phone and restore its factory settings?

1. Tap Settings > General > Transfer or Restore [Device], then tap Erase All Contents and Settings.

2. Enter your screen lock password or Apple ID password according to the prompt, and then confirm that you want to erase the content on the device. Forgot the screen lock password or Apple ID password?

3. Wait for the device to erase the content. It may take several minutes to completely erase the data on the device, depending on your device.

Learn more about how to restore your iPhone, iPad or iPod touch to factory settings.

For additional assistance, please contact Apple Support.