All mobile phones, as well as other cellular-connected devices such as tablets, have a unique serial number. There have been a few different names and formats for these serial numbers over the years, including ESN, MEID, and IMEI. At present, smartphones and tablets have an IMEI. Keep reading to learn more about each of these serial number formats, and why they are so important.
What is an IMEI number?
Essentially, the IMEI is a unique identifier for cellular-connected devices such as phones and tablets. And, depending on the make and model of your phone or tablet, you may even have more than one IMEI. Some common questions regarding IMEI numbers include:
- What does IMEI stand for? IMEI stands for International Mobile Equipment Identity.
- How many digits is an IMEI? The IMEI number consists of 15 digits (all numbers).
- Do all phones have an IMEI? Yes, all phones (and cellular-connected tablets) have an IMEI number. Some, such as newer models of the iPhone and iPad will have two IMEI numbers — one for the physical SIM and one for the digital SIM.
- What is an IMEI number used for? Wireless carriers use the IMEI number to identify devices on their network. Carriers can also use the IMEI number to prevent a device from being activated, such as in cases where the IMEI has been blocklisted.
What is an ESN number and MEID number?
Similar to the IMEI, the ESN and MEID numbers are used to identify mobile devices. The IMEI is the current standard, so that is what you should be looking for if you are buying, selling, or activating a modern smartphone (or cellular-connected tablet).
- What does ESN stand for? ESN stands for Electronic Serial Number.
ESN numbers first came to use in the early 1980s. An ESN was either an 8-digit hexadecimal number or an 11-digit decimal number. ESN numbers were used to identify devices with CDMA carriers such as Sprint and Verizon.
- What does MEID stand for? MEID stands for Mobile Equipment Identifier.
MEID numbers were created in the mid-2000s (after unique ESN numbers were exhausted). The MEID number is a 14-digit identifier for smartphones and other devices connected to a cellular network. The MEID number was commonly used by CDMA carriers, such as Sprint and Verizon.
Is IMEI the same as a Serial Number?
The IMEI and ESN (Electronic Serial Number) are similar in that they are both used to uniquely identify a mobile device, but they are not the same. The ESN was used by CDMA carriers such as Sprint and Verizon, and the IMEI is used by GSM carriers such as T-Mobile and AT&T. The ESN and IMEI also differ in format, with the IMEI being a 15-digit number that is made up of 14-digits with one check digit.
Is MEID and IMEI the same thing?
Similar to the comparison between the IMEI and ESN, an IMEI and MEID are similar in that they are both numbers used to uniquely identify mobile devices. But that said, they are different in that MEID numbers are no longer used. Another key difference between MEID numbers and IMEI numbers is the number of digits. A MEID number has 14 hexadecimal digits and an IMEI number has 15-digits (14-digits with one check digit).
Why is it important to check a phone’s IMEI?
Checking the IMEI is important because it helps determine whether the phone has been reported as lost or stolen.
If you are buying a brand-new phone from a manufacturer like Apple or Samsung, or directly from your wireless carrier — you really shouldn’t worry too much about the IMEI. Similarly, if you are buying a gently used phone from a trusted marketplace like Swappa, you don’t have as much to worry about because Swappa staff checks the IMEI before approving a listing for sale.
On the flip side, if you are buying a phone from another person — you will want to check the IMEI. Fortunately — it is easy (and free) to check an IMEI. To run an IMEI check, you first need to locate the IMEI number(s) in the phone settings. Once you have the IMEI number, you can use Swappa’s Free IMEI Check to determine whether the IMEI is clean (on the Allowlist) or if there are any reported issues (on the Blocklist).