There are a whole lot of problems unrelated to functionality that can pop up when buying a used phone off of a site such as eBay. Here are some of the main ones.
It should go without saying that you should watch out for purchasing a stolen phone. Of course, nobody wants to buy a phone that is the property of someone else, but besides that you might just be buying a fancy paperweight if you end up buying a stolen device. If a device is reported as stolen it will show up in IMEI databases as blacklisted and phone companies will not activate the phone. Even if it is not reported as stolen phones now have safeguards in place in the form of security features such as Find My iPhone (FMI). If the FMI feature is turned on in an iPhone you will not be able to use your Apple ID to sign into the phone until the FMI is turned off and the current Apple ID is signed out of, which requires the password. In addition, if the phone is currently set up (hasn't been reset) that phone can be found by the owner anytime it can connect to data. Other phones besides iPhone have similar systems in place. Obviously, all of these features are great for protecting owners of these phones but they practically ensure that unsuspecting buyers will have nothing to show for their money.
What can you do about it? The good news is there are many websites in which you can look up the IMEI (unique identifier) of the phone and find out its status. (It is best to use several sites because sometimes the sites will show different results. A google search will bring up many sites.) Most of the sellers on sites such as eBay do not automatically provide the IMEI number for you. If they do not then make sure to message them and ask if they will share it with you. Most sellers will be willing to share the number with you. Some refuse to on the grounds that the number can be used for nefarious purposes (Some people claim a phone can be hacked with the number. Others claim the number can be replicated on another phone to change the phones identity. If it is possible it is exceedingly rare that these things happen). I understand those seller’s hesitation's but I shared the IMEI from every phone I sold as a refurbisher and never had a problem. If that's what they think is best for them that is their right, but I certainly wouldn't buy their phone without being able to look up the IMEI. And often a seller is refusing because he knows what you will discover when you look it up. Usually the IMEI is located in the settings somewhere. On iPhone it is in Settings>General>About. If you have trouble finding it you can always type *#6*# on the phone's dialer and it will bring up the IMEI for you.
Another thing you must be wary of is buying a phone that is still under financial obligation or contract with the carrier from whom the phone was purchased. If the phone is still under contract you can typically still use that phone with the carrier who sold the phone, but I don't know if that is always guaranteed. In my experience you will not be able to unlock the phone for resale or if you want to switch carriers when the phone is still under contract. You may be able to convince the carrier to allow you to pay off the phone so it can be unlocked, but again, in my experience they will not allow you to. So in general it is simply best to steer clear of buying a phone that is under contract.
Just as with checking on a phone's blacklist status using the IMEI number, you can also check if a phone is under financial obligation. These are the two sites that I typically use for checking with the different carriers. I use http://imeipro.info/ to check AT&T, T-Mobile, and Sprint phones. You go to the carrier drop down at the top of the page and select the desired carrier. This is the primary site I use to check blacklist status as well. I use https://imei24.com/ for Verizon phones. There is a bigger selection of phones that can be checked on this site as well. Plus on this site you can check the lock or activation status for iPhones for free, whereas imeipro.info charges to check that. If you want to check the financial status of a phone for a different carrier I would recommend contacting the carrier directly and inquiring. In fact, it is always best to contact the carrier directly because in my experience these checkers can come up incorrect. Sometimes it will list a phone as under contract that in fact is not. Sometimes it won't show up as under contract when it is. It is always best to contact to the carrier to be sure.
A word of caution, however. There have been a couple times that I have checked phone IMEIs and they came up financially free and clear, but after I purchased, received and refurbished the phone I re-checked the financial status before reselling and they came up as under contract. In one instance I was able to get my money back. In the other instance, the 3 month window of time had elapsed for me to return the phone on eBay, so I was up poop creek. The problem I believe is these carrier IMEI checkers tell you if the phone is in good standing financially in some cases. When the owner sells the phone and does not pay off the remainder of the balance on that contract that is when the phone shows up as under financial obligation. Obviously, there is no way for the purchaser to avoid this. The best you can do is look closely at the seller's history and make a decision on if they are trustworthy from that.
To be continued in next blog. Thanks!
Jeff - Tech Jedi - Quality Device Repairs