Before you erase a phone you plan to sell, open the maker's own documentation and work through it with a short checklist. On Android, use your phone maker's reset instructions. This piece doesn't yet have verified details from either company, so it sticks to what to check rather than what the answer is. Be wary of any page that gives a quick verdict without naming and linking Apple's or Google's documentation.
This matters most in one common situation: you are handing your old phone to a buyer, a trade-in shop or a relative. The wipe is the last thing standing between your photos, messages and accounts and a stranger. A half-remembered tip from a forum is not good enough for that.
Four questions to answer from Apple's documentation before erasing an iPhone
Open Apple's support guide and look for answers to these, writing down what it says and in what order:
- Backup. Check whether the guide mentions backing up the phone. If you want to keep your data, back up before anything is erased.
- Signing out. Check whether the guide mentions your Apple Account or iCloud, and whether signing out is listed as its own step before the erase or described as part of it.
- Erasing. Find any erase step and note anything it says must already be done before you start.
- Activation Lock and your device list. Check whether the guide mentions Activation Lock or removing the phone from your list of devices, and if so, whether that comes before or after the erase.
Then follow the steps in the order you wrote down. The searches "sign out of iCloud before selling" and "erase all content and settings before selling" are popular because people want to know whether one step covers the other, and the sequence in Apple's documentation is what settles it.
What to check on Android and Samsung phones
Samsung owners can start with Samsung's US support answer. Before you reset, get an answer to each of these:
- Does Factory Reset Protection apply to your phone, and what will it ask of the next person who sets it up?
- Do you need to remove your Google account from the phone before resetting, rather than after?
- Does the maker say anything about whether data can be recovered after a reset?
Where to look for whether a reset is permanent
"Does factory reset delete data permanently" is the question behind most of this, and the one most likely to get a confident but unsupported answer online. Wikipedia's page on factory reset explains the general concept, but treat it as background, not as instructions for your phone. If a third-party blog disagrees with the maker's documentation, go with the maker.
If the documentation leaves a question unanswered, ask the maker's support before you hand the phone over, not after.
