4 Things You Absolutely Must Know Before Buying a Used iPhone (Video)

It’s that time again. A new iPhone has been released and that means two things —it’s time to sell your current iPhone to get some money to help pay for the new one, or it’s a good time to look on Craigslist and eBay for the older models that have just dropped significantly in price.

For those of you looking to do the latter, there are a few things you absolutely need to know before you get started to save yourself a potential hundreds of dollars worth of headache.

Check for a Clean ESN / IMEI

The first thing to check is if it has a “clean ESN”. When perusing Craigslist or eBay for used iPhones, you will undoubtedly find more than one with the words “clean ESN” or saying that the IMEI is clean.

When an ESN or IMEI isn’t clean, it means that it was reported as stolen or someone has missed enough payments on their phone payment plan. The carriers here in the US have a blacklisted database of IMEI/ESNs that they use to tell each other to never activate this device on their networks, ever.

Once blacklisted, there is no way to get unblacklisted and even if the device is unlocked to work on any carrier, you can’t use it on any of the ones here in the States —it’ll just say invalid. You can however, use it on carriers outside the States still since they don’t have access to that blacklist, but click the link below for how to get it to work overseas.

So when looking through listings, make sure it says that the phone has a clean ESN or ask the seller if it is clean before considering it if you’re here in the States.

And, let’s be real, Craigslist isn’t the most trust worthy of places so when you arrive check to see if the phone is actually clean by asking the person to see the phone and then do the following.

Check the IMEI to Make Sure It’s Clean

IMEI is Clean

1. Turn it on.

2. Go to Settings > General > About and look for the IMEI.

3. Then on your own phone, go to swappa.com/esn and put in the IMEI there without any spaces or dashes and click check ESN.

4. It’ll come back and let you know if it’s clean or not and then you can proceed with the purchase or scream at the guy for lying.

Check for an iCloud Lock

The next term you need to know when buying a used iPhone is iCloud lock. I can’t tell you how many emails I’ve gotten from people saying they bought a phone on Craigslist and now it is asking for an iCloud password that they don’t have and won’t let them use it at all.

I feel horrible, it’s a huge problem and shame on Apple for not educating people on this, but once that happens on the phone, there is really no good way of getting past it. Those people now have a very expensive paperweight.
To avoid this fate, whenever you buy a used iPhone, ask if it has iCloud removed and, again, check it and make sure when you arrive to buy the phone from Craigslist (eBay has less of an issue as you can use Paypal to get a refund, but still a pain):

Remove iCloud

Sign Out of iCloud

1. Go to Settings > iCloud, scroll all the way to the bottom, and tap Sign Out.

2. It’ll ask for a password at this point, tell them to enter in their password so you can remove the iCloud account and tell them it also removes their personal data from the phone so it helps them, as well.

If they refuse, don’t buy it. It’s a phone they found at a bar and they’re trying to make a quick buck on. What will ultimately happen, is whenever that original owner gets around to claiming it as lost, it’ll lock up as mentioned before and you’re out of luck.

Check for Water Damage

The next big thing you need to check is water damage.

A phone with water damage might still work, but the issue with a water damaged phone is that, generally, eventually, it starts to affect the internals, especially if it wasn’t dried out properly. So it’s best to avoid buying water damaged devices at all.

Liquid Contact Indicator Chart

Each iPhone has a water damage indicator though that you can see and check really quickly if the phone itself has water damage before you buy it. This indicator is essentially a sticker located somewhere on the device that when exposed to moisture, turns from white or silver to red. If the indicator has any redness to it (even if it’s pinkish), don’t buy it. It won’t turn that color from humidity or something similar, it needs to have touched a liquid. Period.

Locate the Liquid Damage Indicator on iPhone 4S or Older

Liquid Indicator iPhone 4

On older iPhones, the 4S and below for example, there are two indicators on the device. You can find them by:

1. Checking the headphone port. Inside you can see it by holding the device up and looking down into the port (the flashlight feature on your current phone will help with seeing it by the way).

2. There’s also one more inside the charging port as well, make sure to check both as maybe just the bottom of the phone was dunked but the top wasn’t or vise versa.

Locate the Liquid Damage Indicator on iPhone 5 or Newer

Liquid Indicator iPhone 6

On newer iPhones, the 5 and up, there’s only one indicator and it’s inside the SIM card slot. To get to it do the following:

1. Using a thin paperclip or something similar, pop out the new SIM card tray.

2. With the phone facing downward, you’ll see the hopefully white and not red dot inside.

Check if It’s Locked and Works on Your Carrier

SIM in iPhone

While you have that out by the way, you want to put in your own SIM card into that tray and turn the phone on to make sure it works with your carrier (and that they weren’t lying about the carrier they said it was for). There is a way to unlock the phone if it doesn’t work for your carrier, but there are even limitations to that as well, for more info click the link below, but its easiest to just check and make sure it works off the bat.


These four things are the biggest things to have to check when buying a used iPhone but also make sure to check the normal things, look for wear and tear, turn it on, swipe the screen and make sure certain parts of it aren’t “dead”, open the camera app and make sure both cameras work and don’t have scratches on them, etc. and, finally, do research online to see what the phone is selling for to make sure you get the best price on it.

Completed Listings on eBay


On eBay, you can even click completed listings in the revising of your search and see what they actually sold for and not just what people are trying to get for them but never will.

Hope this helps you guys, and if it did and/or if you have any other tips for people buying used iPhones post in the comments below!

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1 thought on “4 Things You Absolutely Must Know Before Buying a Used iPhone (Video)”

  1. David, thanks for including the free Swappa ESN check tool in your article. After using our ESN check, why wouldn’t you buy or sell your iPhone right on Swappa, too? We’re a human powered marketplace that is less expensive and offers a much safer option than eBay and Craigslist. Hope you’ll give us a try for buying and selling. Thanks!

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