With your photos, email access and bank details stored inside, smartphones and tablets can contain a wealth of data that you need to remove before selling or giving the handset away. If you're selling or binning an Android phone or tablet, it's important to erase your data first.
For business users with more sensitive documents, it's also worth considering encrypting the data on your phone or tablet. You would need to do this while still actively using the device (ie before you're considering wiping it).
Encryption will protect even residual data that could still be recovered from your device using data-recovery software. For most users, we wouldn't recommend encryption as being necessary, but if you're confident with what you're doing, or if you have particularly sensitive documents to protect, then it's something worth considering.
Factory reset an Android device
Frustratingly, with handsets based on the Android operating system, there are no quick-fix solutions, but protecting your data is still possible. The accepted wisdom is that users should factory reset their handsets.
To get to this option, tap Settings > General > Backup and reset. The path can vary subtly depending on which manufacturer of phone you use.
You should find that Back up my data is already ticked, with your Google (gmail) account selected. This means that you can recover a saved mirror version of your Android device and its data - useful, if you're setting up a new phone or tablet to replace your current one.
Under this, look for the option for Factory data reset. Tap this, and you'll see a screen explaining what will happen if you continue. Tap Reset device at the bottom if you're happy to proceed.
Can my data still be recovered?
Researchers have found that this process still leaves some user data on a smartphone or tablet’s storage – data that can easily be reinstated using fairly cheap software. For most home users, the risk of this happening is small enough that you shouldn't feel too concerned.
However, for the particularly security-conscious, you may wish to consider encrypting your Android device's data (see below). This is something you can do while you're still actively using the device - ie before you're considering wiping it and selling or binning it.
Encrypt the data on an Android device
Encrypting your phone’s storage means that if anyone did try to access the residual data on a phone or tablet, even after you'd factory reset it, they couldn’t read it without a password.
Choosing to encrypt your phone isn't to be taken lightly - the process can take time (you'll need your battery to be at least 80% full) and you can't interrupt the process once it begins. Doing so could risk damage or loss to your data.
Do you need to encrypt your device?
If you keep sensitive business materials on your Android device, then you should consider this option. If you work for a company, speak to your IT department for their advice before attempting to encrypt your tablet or phone.
For home users, encryption is less pressing. Your personal photos and documents aren't something you'd want salvaged by a data thief using recovery software, but the likelihood of your wiped, second-hand or discarded device being targeted like this is relatively small. Any banking and shopping apps you use on your phone already have encryption built-in, and won't leave behind residual data that could be recovered from a wiped device.
Keeping your device locked by a secure password, Pin, pattern or fingerprint-lock is far more important for most home users than delving into encryption settings.
If you do wish to encrypt your data, decide if you want to remove the microSD card inside your Android device first. Some (though not all) Android tablets and phones let you add a memory card to boost the storage space, and your photos and files can be saved here.
There's no harm in encrypting the data on the microSD card (so long as you remember your own password!), but be aware of whether you're doing so or not.
On most Android handsets, head to Settings, then Security and then select Encrypt phone to begin the process. Again, we would warn that it takes time and must not be interrupted once you begin.
Android SIM and microSD cards
Don’t forget to remove your SIM card and any microSD cards before parting with a phone. These can contain data on them that you may want to keep, or certainly wouldn't want others to have.