Do this before you upgrade your phone: Back up your data and wipe it clean

Tempted to upgrade to a shiny new iPhone or Galaxy device? Or perhaps you're waiting for the Google Pixel 4a announcement?

Upgrading to a brand-new device is exciting—especially if your current phone can barely handle a game of solitaire—and to make it even more enticing for you, many phone providers and retailers offer a trade-in incentive.

Sounds reasonable, you think, as you probably don't need your old hardware anyway and you'll get cash off your new device.

There are a couple of things you need to do beforehand, however, which includes backing up your important files and properly wiping your device clean of your old data—to reduce the odds of it falling into the wrong hands. (With that in mind, ask your carrier or retailer what they do with your old device, as some companies may sell it overseas.)

So long as you take these two precautions and stick with a reputable place to trade in your old phone, you shouldn't have anything to worry about. If you're really concerned about the risks, don't trade in your phone, of course.

Back it up

The first thing you should do is properly back up your phone's files, so you can access them later. You may want to load them back onto your new phone or at the very least, access your photos and videos on a computer or television in the future.

One option is to upload images to a cloud provider, such as iCloud, Google Drive, OneDrive, or Dropbox. Typically, you'd get about 5 gigabytes of remote storage for free, but this likely won't be enough for you, so you might consider paying for more.

Personally, I use OneDrive, as it offers 1 terabyte of storage (more than 1,000GB) as part of the annual Microsoft 365 Personal subscription ($69/year). If you have a healthy data plan, you can also have all captured photos automatically saved to a cloud account, as soon as you take them.

The Google Photos app is also a great idea, as you get free and unlimited storage for all your photos and videos, up to 16 megabytes per photo and up to 1080p HD video quality. Amazon Prime members ($119/year) can also take advantage of Amazon Photos, offering unlimited photo storage and search and organization features.

Another suggestion is to copy over photos and videos from your smartphone to a PC or Mac. Simply connect the device to a computer via its USB port, and in Windows Explorer (for Windows) or Finder (on a Mac), click the drive letter of your phone or tablet (such as D: or E:), and enter the folder called DCIM, which holds all your captured photos and videos. They may be in subfolders, but they'll all be here. Now manually drag and drop (or cut and paste) them onto your computer or an external drive.

With iOS devices, like iPhone and iPad, you should do a complete back-up—to iCloud or a connected computer (which is free!) – and then import all the apps and data back onto the new device, if desired.

In other words, there are several ways to back-up the contents of your phone—so long as you do something.

Properly wipe the device

Before you trade in your old phone, it's absolutely critical to properly wipe the data clean.

Choosing to "restore" or "factory reset" your device will work—if encrypted.

For Android users, if your existing phone runs Android 6.0 (Marshmallow) or newer, your data will already be encrypted by default. So, you're good there.

If you've got an older Android OS, you'll want to add encryption as it will require someone to have a PIN or password to access your data. In most cases, go to Settings > Security & privacy > Encrypt phone. It can take a while for this process to complete, so be sure to have your phone plugged into an AC outlet. On a Samsung Galaxy, you'll go to Settings > Lock screen and security > Protect encrypted data.

You'll have the option to encrypt the SD memory card as well, if your phone takes one and you have one installed, but you should remove this external storage anyway if you're giving away your phone. Be sure to also sign out (and then delete) your accounts, such as Google and Samsung (on a Galaxy device), just to be safe.

Now go ahead and do the factory reset, which is usually found in the Reset tab in your Settings (or do a search for the word "reset" and it should take you to the correct section).

For iPhone, iOS 5 or later also includes hardware encryption when you set a passcode. This makes it difficult for anyone who tries to recover your data.

First, be sure to turn off all services, starting with Find My iPhone (Settings > [Account Name] > Find My), and then signing out of iCloud completely. Now choose Delete Account. Sign out of other services, like iMessage, and Apple ID.

Now start the wipe process by going to Settings > General > Reset > Erase All Content and Settings.