What is bad ESN iPhone? Almost all answers regarding to bad ESN are here

Nowadays, cellphone plays a very important role in our daily life. We almost do all email checking, Facebook sharing and something like those via our iPhone. But how if someday our iPhone cannot receive any message, phone call and social network notification? Can you bear this situation? DEFINITELY NO! A bad ESN iPhone will largely increase the risk of suffering this. So, what is bad ESN iPhone? Why our iPhone ESN goes bad? Here are those answers.

What is ESN and what does bad ESN mean?

An ESN is the Electronic serial numbers assigned to your iPhone. It is used with CDMA phones instead of SIM cards. We already know that any iPhone will be issued an IMEI, but only CDMA iPhone will be also issued an ESN. (Click here to know more about iPhone GSM /CDMA models)

A bad ESN iPhone means you cannot activate that iPhone or use cellphone service on some specific carriers. For example, if an iPhone blocked by Verizon, then that iPhone will not be activated on Verizon network.

In one word, a clean ESN CDMA model iPhone (such as Verizon and Sprint) will become bad ESN iPhone after carrier block it.

As to carrier-blocked iPhone, there also has a counterpart for GSM model iPhone (such as AT&T and T-Mobile): bad IMEI iPhone. In one word, a clean IMEI GSM model iPhone will become bad IMEI iPhone after carrier block it.

Why an ESN/IMEI goes bad?

You may ask, why the ESN/IMEI always become bad ESN/IMEI? There have several reasons that could cause a clean ESN/IMEI become bad ESN/IMEI.

1. If an iPhone still have unpaid balance or it is still under financed status, Carrier will add that ESN/IMEI to their blacklist database and block it. Then, that ESN/IMEI will go bad.

Nowadays, we can easily purchase a new released iPhone via Carrier installment plan or enjoy huge discount with certain contract monthly plan. It is so great for many iPhone buyers to get their dreaming iPhone especially when they have no enough budget to purchase a full price one. Normally, a buyer will take 12 to 24 months to get this brand new iPhone paid off. But how if a buyer only pays the installment bill several months then refuse to pay? That iPhone will be definitely blocked by the carrier due to the unpaid balance or financial balance.

To check the new released iPhone X on E-Bay right now, there have tons of bad ESN/IMEI iPhone X with super cheap price (almost around 40%-50% off the full price without sales tax charge) for sale every day. Most of them are under this situation.
A Lost or stolen report will cause clean ESN/IMEI turns to bad ESN/IMEI.

Unlocked iPhone does NOT mean a clean ESN/IMEI

Some used iPhone buyers may believe that if they purchase an unlocked iPhone, the ESN/IMEI must be clean. They also have a very reasonable reason for that: if previous owner own money to the carrier, carrier will not unlock that iPhone for them; if an iPhone is unlocked, its ESN/IMEI must be clean.


1. An unlocked iPhone might be reported as lost or stolen, which can still make the ESN/IMEI not clean.

2. IPhone unlocking process can be done not only by cellular carrier, but also can be done by Apple and third party unlocking service provider. Carrier is not the only one who can get the locked iPhone unlocked.
Carrier for sure will try their best to prevent the bad ESN/IMEI iPhone getting any service from them, but once the iPhone is unlocked, that iPhone may get service from other service provider.

Should we buy a bad ESN/IMEI iPhone?

Typically, We should not buy a bad ESN/IMEI iPhone when we intend to purchase used iPhone. Buying a used bad ESN/IMEI iPhone may make trouble for us on our daily use.

But sometimes we do not even know that we purchased a bad ESN/IMEI iPhone. Also, ESN/IMEI status may change at any time and no one can guarantee that the ESN/IMEI will not turn bad after we make purchase. All we could do is to try our best to prevent buying a bad ESN/IMEI iPhone.

Also, different people might have different purpose for purchasing used iPhone. It’s really hard to say we should or we should not buy them. For example: Someone might need an iPhone to test program or iOS APP, the bad ESN/IMEI almost cannot make any impact in this situation.

How to fix a bad ESN/IMEI iPhone?

In the future, we should know our purpose before we buy used iPhone and try our best to get a clean ESN/IMEI iPhone. But as we talked before, no one can guarantee an iPhone has a clean ESN/IMEI forever. How if we fix a bad ESN/IMEI iPhone if the ESN/IMEI go bad?

WE HAVE TO CLAIM A FACT HERE: bad ESN/IMEI means the ESN/IMEI is in the carriers blacklist, THE ONLY WAY to fix a bad ESN/IMEI is to let carrier remove the ESN/IMEI from the blacklist.

Method 1. Contact Carrier for help. You can contact the carrier to ask for reasons why they put your IMEI in the blacklist. If there still have outstanding balance on the account or phone, you have to pay it to clear bad ESN away.

Method 2. Ask refund from seller. If you purchased online or from trusted seller, you can return it back and ask refund.

Method 3. If your iPhone still under warranty, you can find ways to get this iPhone swapped or replaced by Apple. As we talked before about iPhone replacement, Apple will replace the whole phone or logic board when they repair the phone. In this way, your old iPhone will be swapped and you will get an iPhone with different ESN/IMEI. In this way, your bad ESN/IMEI is going to be replaced to a brand new ESN/IMEI, which will not appear on carrier’s blacklist database. There has lot of iPhone swap service on E-Bay (picture below shows the result on E-bay search). We actually do not recommend doing this, but it is really a way if you really need to fix the bad ESN/IMEI.

WRONG WAY TO FIX BAD ESN/IMEI: There also have a way to fix the bad ESN/IMEI, but it is not a right way and you may waste your money and time on that. Some people or service provider will tell you that they can clean the ESN/IMEI and make your bad ESN/IMEI clean again. All you need to do is send them your ESN/IMEI number and waiting for like 24 to 48 hours, then your bad ESN/IMEI will turn into clean ESN/IMEI. Yes, your ESN/IMEI will go clean for a while but when you use the service provided by the carrier, the carrier will detect your device ESN/IMEI and your phone will be re-blocked by carrier. All your money is just paid for a temporary cleaning service.

Always check ESN status before you buy

We already know that how the ESN/IMEI go bad. We should always check the ESN status before we make purchase to best match our requirement. Next topic we will talk about is how to check ESN/IMEI status for iPhone or cellphone.







  1. I actually had no idea that something like this existed! Certainly a great article teaching me that although it might be a lot more expensive, buying a new phone could alleviate a lot of potential headaches! Thank you for the great article and the education about ESN status!

    • Thank you. Yes, ESN status is very important when we decide to buy used iPhone or cellphone. Next article we will share about how to check ESN accurately and for free.

  2. Hi Peter, thank you for opening my eyes to this potential problem. I had no idea about this and your article has been very helpful and educational.

    I have a question, is this bad ESN problem only with iPhones or are you aware if this can happen with Android phones too?

    • Hi Moni, every phone has ESN/IMEI no matter is is iPhone or Android. But we can check ESN/IMEI via almost same way. Also, Android phone use different way to get unlocked, it is easier for android user get rid off the bad ESN/IMEI. I will go ahead to write something about how to check ESN/IMEI status in the next article.

  3. Really good, useful information about buying used iphones. I had no idea that this was the case, but it does make sense. I have been thinking of upgrading my old iphone4 for some time, but I hesitate to buy a new one because of cost. This information will help me to make a smart buying decision. Thank you for sharing.

    • Yes, always check ESN/IMEI status before you buy used iPhone or Android phone. Or you already know that what are you buying to prevent money and time wasting.

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