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Trade-in season is coming, and with new iPhones weeks away, millions of phones are about to change hands. Most of their owners will do the one thing everyone knows, a factory reset, and skip the steps that actually matter. The results fill resale forums every autumn: buyers staring at a lock screen demanding the previous owner’s password, and sellers locked out of their own bank accounts because their two-factor codes died with the old phone.
Both disasters are completely avoidable, and the entire secret is doing things in the right order. Here it is, start to finish.
The Order Matters More Than the Steps
Write this sequence down, because every horror story comes from shuffling it: back up, move your authenticators, sign out of accounts, handle the SIM, then reset, then verify. The reset is nearly the last step, not the first. A reset done before the sign-outs creates a phone locked to your account that no buyer can use. A reset done before the authenticator migration locks you out of everything protected by those codes. Order first, taps second.
Step 1: Back Up Like You Mean It
Run a full backup: iCloud or a computer backup for iPhone, Google’s backup for Android. Then check the two things full backups famously fumble. Photos: confirm your library has actually finished syncing to iCloud or Google Photos, not just started, and if you’re near your storage cap, sort that first, which is a problem we’ve covered in depth for both ecosystems. WhatsApp: run a fresh chat backup manually from inside the app, since an outdated one silently costs you weeks of messages, and if you’re switching platforms entirely, know that cloud backups don’t cross the iPhone-Android border, a wall we’ve mapped in both directions.
Android users: pop out any microSD card now, while you’re thinking about it. Cards survive factory resets untouched, and handing a buyer your photo collection on a card is a classic self-inflicted breach.
Step 2: Move Your Two-Factor Apps (The Lockout Trap)
Here’s the step almost no guide puts this early, and it belongs here because it’s the one that hurts you rather than the buyer. Authenticator apps do not automatically survive a reset. If Google Authenticator, Microsoft Authenticator, or similar lives on this phone, those six-digit codes guarding your email, banking, and everything else can die with it.
Before anything gets erased: enable cloud sync or run the explicit transfer-accounts flow in your authenticator, set it up on the new phone, and generate a working code on the new device to prove it. Download backup codes for your most important accounts while you’re at it. The people who skip this step are tomorrow’s readers of our account recovery guide, which is a fine article I’d rather you never need.
Step 3: The Activation-Lock Mistake That Bricks the Sale
Every modern phone has anti-theft protection that survives a factory reset by design: Activation Lock on iPhone, Factory Reset Protection on Android. Reset without removing your account and the phone stays cryptographically tied to you, leaving the buyer stuck at a setup screen asking for credentials they’ll never have. This isn’t rare; it’s the single most common used-phone dispute, and it’s also why a locked phone is worthless to legitimate buyers.
- On iPhone, the current erase flow handles this properly if you let it: when you run the official erase (next section) and enter your Apple Account password when prompted, Find My and Activation Lock switch off as part of the process. Two extras Apple itself recommends: unpair your Apple Watch first if you have one, and if you’re moving to Android, deregister iMessage so your texts don’t vanish into a blue-bubble void. Remove your cards from Apple Pay too.
- On Android, do it manually before the reset: Settings, then your accounts section, and remove your Google account. On a Samsung, remove the Samsung account as well, since it enforces its own lock. With accounts removed, the reset releases the phone cleanly.
Step 4: eSIM, Transfer, Don’t Just Delete
A step that didn’t exist a few years ago and now trips people constantly. If your number lives on an eSIM, your goal is moving it to your new phone, not destroying it. Transfer first: new iPhones offer a quick eSIM transfer during setup, Android varies by carrier, and some carriers require a fresh activation from their app or a store. Only once your number is alive on the new phone should the old one’s profile go, and the iPhone erase flow will explicitly ask whether to erase the eSIM along with the device, which is the right moment to say yes. Delete the eSIM before securing the transfer and you can end up cut off from your own number, along with every OTP it receives, a dependency we’ve written about in the travel context. Physical SIM users have it easy: eject the tray, keep the card.
Step 5: The Reset Itself
With everything above done, the actual wipe is the easy part.
- iPhone: Settings, General, Transfer or Reset iPhone, Erase All Content and Settings. Enter your passcode and Apple Account password when asked. The phone reboots to the “Hello” screen.
- Samsung: Settings, General management, Reset, Factory data reset.
- Pixel and most other Androids: Settings, System, Reset options, Erase all data (factory reset). Menu wording varies slightly by brand, but it always lives under Reset.
Then verify, which is the step everyone skips: the phone must sit at the Hello or welcome screen, and setup must proceed without asking for your account. Do not sign back in “just to check”; that re-arms the locks. Final proof: open your Apple or Google account on another device and confirm the old phone has vanished from your device list. Screenshot that, and photograph the phone on its setup screen, cheap insurance against any later dispute.
Is Your Data Really Gone? The Honest Answer
Time to retire some folklore. You’ll still find advice about resetting, filling the phone with junk files, and resetting again to overwrite your data. That ritual made sense a decade ago. It’s obsolete now, and here’s why: every iPhone and effectively every Android of the last many years encrypts its storage by default, and a factory reset destroys the encryption keys. Without the keys, whatever fragments remain on the chips are permanent gibberish, unreadable even with forensic tools. For any phone recent enough to be worth selling in 2026, a proper reset after proper sign-outs means your data is genuinely unrecoverable, full stop.
The honest caveat lives at the margins: ancient Androids from the pre-encryption era were a real recovery risk, so a truly old device is better recycled than sold. And remember the reset only protects the phone itself; your cloud accounts, and anything you stayed signed into on the web, are their own responsibility.
Quick Answers
- Is a factory reset enough before selling a phone?
Only if you sign out of Apple, Google, and Samsung accounts first and migrate your authenticator apps. The reset is the last major step, not the whole job. - What happens if I forget to turn off activation lock?
The buyer gets an unusable phone locked to your account, and you get a dispute. Fix it remotely by removing the device from your Apple or Google account on the web. - Can someone recover my photos after a factory reset?
On modern encrypted phones, no. The reset destroys the encryption keys, making leftover data unreadable. The old junk-data-overwrite trick is unnecessary on current devices. - Do I lose my number if I erase a phone with an eSIM?
You can, if you delete the profile before transferring it. Move the eSIM to the new phone first, then erase the old device and its profile. - Should I take out the SIM card?
Yes, physical SIM and any microSD card both come out and stay with you. Neither is wiped by a reset.
The Bottom Line
A used phone changes hands cleanly when six things happen in order: a verified backup, authenticators moved and proven on the new device, every account signed out so the anti-theft locks release, the eSIM transferred before anything gets deleted, the official reset run to the Hello screen, and a final check that the phone has left your account’s device list. Skip the order and you either brick the sale or lock yourself out of your own life. Follow it and modern encryption does the rest, leaving nothing behind but a phone that’s genuinely, provably no longer yours. And if you’re timing all this around September’s launches, remember the other half of the equation we covered already: lock the trade-in value before the event, wipe the phone after.
