How to Wipe Your Phone Before Selling or Trading It In

People hand their phones in all the time and only afterwards think to ask whether their data is really gone. Sometimes they’ve done a factory reset but left Find My switched on, which means the next owner gets a very expensive paperweight that’s locked to your Apple ID. Sometimes they’ve just deleted a few apps and assumed that’s enough. It isn’t.

The good news is that wiping a phone properly takes about ten minutes if you know the order to do it in. The key word there is order. Do it backwards and you can leave yourself locked out of the reset, or worse, leave your data accessible to whoever picks the phone up next. Here’s how to do it right.

Back Up First

Before you touch anything else, back up. Once you’ve wiped the phone, what’s gone is gone.

iPhone: The easiest option is iCloud. Go to Settings, tap your name at the top, then iCloud, then iCloud Backup, and tap Back Up Now. Make sure you’re on Wi-Fi and give it a few minutes. If you’d rather have a local backup, plug your phone into a Mac and use Finder (or iTunes on Windows). Connect the phone, find it in the sidebar, and click Back Up Now.

Android: Google One backs up your contacts, photos, app data and call history automatically if you’ve got it switched on. Check under Settings, then System, then Backup to make sure a recent backup exists. For photos specifically, Google Photos syncs in the background as long as you’ve got backup turned on. Some manufacturers, Samsung in particular, have their own backup tools as well. Use whatever you’re comfortable with, but double-check the backup has actually completed before you move on.

Once you’ve got a backup you trust, you’re ready to wipe.

On an iPhone

Apple’s activation lock is the thing that catches most people out. If you don’t sign out of your Apple ID before resetting, the phone stays tied to your account. The buyer cannot activate it, and you’ll need to remove it remotely afterwards. Sorting that out is a nuisance for everyone, so just do it in order.

1. Sign out of iMessage. Go to Settings, Messages, and toggle iMessage off. This stops your number being linked to the device in Apple’s system, so your texts route to your new phone rather than the old one going dark.

2. Turn off Apple Pay and remove your cards. Open Settings, then Wallet and Apple Pay. Remove each card. You can also do this from your bank’s app, but clearing them from the phone directly is the quickest way.

3. Turn off Find My. This is the important one. Go to Settings, tap your name, then Find My, then Find My iPhone, and toggle it off. You’ll need your Apple ID password to confirm. If you skip this step the phone will be activation locked when it resets.

4. Sign out of your Apple ID. Settings, tap your name at the top, scroll to the bottom and tap Sign Out. You’ll be asked for your Apple ID password again. It will offer to keep a copy of certain data on the phone - it doesn’t matter whether you do or don’t, since you’re about to wipe everything.

5. Remove your SIM card. Pop it out with the SIM tool (or a straightened paperclip). Keep the SIM, it belongs with you.

6. Erase the phone. Go to Settings, General, Transfer or Reset iPhone, then Erase All Content and Settings. The phone will confirm what’s about to happen, ask for your passcode, and then wipe itself. It takes a few minutes.

7. Remove the device from your Apple ID account. Once it’s wiped, go to appleid.apple.com on a computer or another device, sign in, find the Devices section, and remove the phone from your account. This is the final clean break.

The phone should now restart to the Hello screen. That’s what you want to see.

On an Android Phone

Android uses something called Factory Reset Protection. It’s designed to stop a thief from wiping a stolen phone and selling it on, which is a good thing. The way it works is that after a reset, the phone asks for the Google account that was logged in before the wipe. If you remove the account before resetting, that screen doesn’t appear and the next owner can set the phone up cleanly.

1. Remove your Google account. Go to Settings, then Accounts, find your Google account and remove it. On some phones this is under Settings, then Accounts and Backup, then Manage Accounts. Removing the account here is what disables Factory Reset Protection.

2. Remove screen lock. If you want to be thorough, remove your PIN or fingerprint under Settings, Security. This is optional, but it ensures there’s nothing left that could trip up the reset.

3. Remove your SIM card and any SD card. Take both out now. The SIM is yours, and an SD card sometimes isn’t wiped by a factory reset, so take it with you regardless.

4. Perform the factory reset. The path varies a bit depending on your phone. On most Androids it’s Settings, then System, then Reset, then Erase all data (factory reset). On Samsung it’s Settings, General Management, Reset. On older phones it might be under Settings, Backup and Reset. Have a search if you can’t find it immediately. Confirm when prompted, enter your PIN if asked, and let it do its thing.

The phone will restart. On the setup screen it should ask the new owner to set up as a new phone without prompting for your old Google credentials.

A Note on Encryption

Modern smartphones encrypt their storage by default. iPhones have done this for years, and Android phones from around 2015 onwards are encrypted out of the box. What this means in practice is that when you factory reset a phone and the encryption key is wiped along with everything else, the data left on the flash storage is scrambled and effectively unreadable, even with specialist tools. It isn’t like wiping an old hard drive where deleted files could be recovered with the right software.

So doing this process properly, sign out first then reset, gives you a phone that’s genuinely clean. The new owner gets a blank device with no route back to your data.

Selling to Us

If you bring your phone in to mendmyi, we wipe and factory reset every device we take in as part of our standard process. We don’t confirm the trade-in or payment until that’s done. So even if you’ve forgotten a step, or you’re not sure whether you’ve done it in quite the right order, we’ll catch it here. You can sell your phone in Haverhill knowing it’s been properly cleared before it goes anywhere.