A factory reset is simple. Doing it in the wrong order is how people lose data permanently or hand over a phone the buyer cannot use.
Before you reset
Back up everything
- Run a system backup and confirm it completed today.
- Confirm photos are fully synced — check on another device.
- Back up WhatsApp manually and note the time.
- Copy files out of Downloads and any non-standard folders.
Deal with authenticator apps
This is the most-missed step and the hardest to recover from. Authenticator apps do not restore from a normal backup. Either enable the app's cloud sync, transfer accounts to your new phone while this one still works, or make sure you have the backup codes for every account. Resetting first can lock you out of accounts entirely.
The critical step: sign out of your accounts
This is what prevents the phone being locked for the next owner.
Android: remove your Google account under Settings, Accounts before resetting. Skip this and Factory Reset Protection will demand your Google credentials after the reset, making the phone unusable for a buyer.
iPhone: sign out of your Apple ID and turn off Find My iPhone, or Activation Lock leaves it unusable for anyone else.
Also remove the SIM and any memory card.
Performing the reset
Android: Settings, System, Reset options, Erase all data. iPhone: Settings, General, Transfer or Reset iPhone, Erase All Content and Settings. Keep the phone above 50 percent charge and do not interrupt it.
Is a reset enough before selling?
On modern phones, yes — storage is encrypted by default, and a reset discards the encryption key, making remaining data unreadable. For extra assurance on an older device, fill the storage with unimportant files after the reset and reset again.
After the reset, before handing it over
- Boot it and confirm it reaches the initial setup screen with no account prompt. If it asks for a previous account, you did not sign out properly.
- Confirm the SIM and card slots are empty.
- Note the IMEI for your records, and keep the invoice if the buyer needs it for warranty.
Wait a week after moving to your new phone before wiping the old one. Something is always missed, and having the old device working makes it trivial to fix.
