’Tis the season when everyone wants a phone upgrade for Christmas. And there are some definite steps to take whether buying or selling a used phone. So before you shell out hundreds of dollars for someone else’s used phone, explore all the options and take some precautions.

Apple sells like-new refurbished phones that meet the same functional standards as new Apple products. The phones will have new batteries and outer shells and come with all accessories and free shipping and returns. Apple gives refurbished phones a one-year warranty with the option of buying Apple Care for more coverage. Currently, Apple sells only the iPhone 7 and iPhone 7 Plus in its online refurbished shop, and you can save up to 15 percent. A refurbished iPhone 7 with 128GB, for instance, is offered right now for $469, which saves you $80. The other great option when buying refurbished is that all the phones come unlocked so you can use them with any carrier.

Samsung sells certified pre-owned phones that are remanufactured to original condition, and also come with new accessories and a 12-month manufacturer warranty. When purchasing from its inventory, you can choose an unlocked phone, or one that works with a specific carrier. A Galaxy S8 with 64GB is available on the site right now for $350, instead of paying $600 for a brand-new one.

Target, Best Buy, Amazon and Walmart also have a selection of refurbished phones, each with their own set of accompanying standards and warranties. Target’s certified pre-owned phones come with one-year limited warranties, phones from Walmart and Amazon have 90-day minimum warranties and the warranties on phones from Best Buy vary. But phones from Best Buy and Walmart come with all original accessories, so don’t forget to take that into account when comparing prices.

If you decide to buy from a personal seller online, you’ll want to make sure the phone will work on your carrier. If the phone is unlocked, it’s a go on any carrier (as are many of the newer phones), but you will want to get the IMEI number to check for sure. The easiest way to find the number for most phones is to enter *#06# into the keypad, and the number will pop up. From there, just search for your carrier’s BYOD or Bring Your Own Device website and enter in the IMEI to find out if the phone will work on your network. Also, let the seller know you’ll want to test a few things before the transaction is complete. When you meet to check out the device, bring along a charging cord to make sure it powers up properly. Also be sure to test out the headphone jack, check the screen and camera for damage and test all the buttons to see that they’re in working order.

There are also important steps to take if you are the one selling a used phone. You want to make sure none of your private information is passed on to your buyer along with your device.

With iPhones, start by backing up your device. If you are switching to a non-Apple phone, deregister iMessage through Settings>Messages. Make sure your Apple watch isn’t paired and then sign out of iCloud and iTunes. Do not mistakenly delete anything while signed in to iCloud with your Apple ID, or it will delete everything everywhere. Finally, go to Settings>General>Reset>Erase All Content and Settings, and your phone is ready for its new owner without any of your personal information.

For Android phones, take out the SIM and SD memory cards if your phone has them. Android phones also have something called Factory Reset Protection to stop bad guys from stealing and wiping your phone. But when you need to legitimately erase information from the device, you’ll need to turn off this protection in Settings>Accounts>Google. When ready to erase the phone, go to Settings>Backup and Reset, and rejoice knowing your private data is no longer connected to that phone.

May your used phone buying and selling experience this holiday season be safe and merry.

Amy Iverson is a graduate of the University of Utah. She has worked as a broadcast journalist in Dallas, Seattle, Italy and Salt Lake City. Amy, her husband, and three kids live in Summit County, Utah. Contact Amy on Facebook.com/theamyiverson