Before you start
Menus vary depending on the brand and the Android version, but the steps stay the same. Have your unlock code to hand, along with the passwords for your Google account and, on Samsung, your Samsung account. Plug the phone in.
Note down the IMEI number (dial *#06#): the buyback company often asks for it, and it identifies exactly which device you sent.
1. Back up your data
Turn on Google backup (Settings > Google > Backup, or Settings > System > Backup depending on the model) and run a backup. Check that your photos are properly synced to your photo service and, if needed, export your messaging app conversations from each app's own settings: they are not always included in the Google backup.
On Samsung, Smart Switch also lets you copy all your content to a new phone or a computer.
2. Remove your Google account
This is the step that prevents the FRP lock. Open Settings > Passwords & accounts (or Accounts, or Accounts and backup, depending on the brand), tap your Google account, then Remove account. Repeat for every Google account on the phone.
3. Turn off the manufacturer's protections
- Samsung: remove your Samsung account (Settings > Accounts and backup > Manage accounts) and turn off Find My Mobile. Otherwise, the reactivation lock stays on after the erase.
- Xiaomi, Redmi and Poco: remove your Xiaomi account (Mi Account) and turn off Find device.
- Other brands: if a manufacturer account or a location feature is active, remove it in the same way.
4. Restore factory settings
- Google Pixel and standard Android: Settings > System > Reset options > Erase all data (factory reset).
- Samsung: Settings > General management > Reset > Factory data reset.
- Xiaomi: Settings > About phone > Factory reset.
On recent Android smartphones, data is encrypted: the reset makes it unreadable. If an eSIM is installed, choose to erase it during the reset, after arranging its transfer with your operator.
When the setup welcome screen appears, go no further: the phone is ready.
5. Check from your Google account
On myaccount.google.com, under Security > Your devices, check that the phone you sold no longer appears, and sign it out if necessary.
6. Get the phone ready to send
- Remove the SIM card and the microSD card.
- Take off the case and the tempered glass screen protector so that its condition can be checked.
- Clean the device.
- Take photos of the phone switched on, from every angle, before packing it.
Has the phone already gone?
From android.com/find (Google's Find My Device) or, for Samsung, from Samsung's device-finding service, you can erase the phone remotely if it is connected to the internet. Then remove the device from your Google account.