The Definitive Guide to AT&T IMEI Checks: Compatibility, Unlocking, and Security

Part 1: The Foundation: Understanding the IMEI Number

 

Every mobile device, from the latest smartphone to a cellular-enabled tablet or smartwatch, possesses a unique digital identifier that is fundamental to its operation on a global scale. Understanding this identifier is the first step toward navigating carrier policies, ensuring device compatibility, and protecting oneself in the used phone market.

 

What is an IMEI Number? The Fingerprint for Your Phone

 

The International Mobile Equipment Identity, or IMEI, is a globally unique 15-digit serial number assigned to every mobile device that connects to a cellular network.1 It functions as a permanent fingerprint for the physical hardware itself.3 Mobile network operators like AT&T rely on this number to perform their most basic functions; they use it to verify that a device attempting to connect is valid and authorized for use on their network.5

Embedded within this 15-digit code is information about the device’s origin, its manufacturer (brand), specific model, and year of release.5 This is how a carrier’s system can instantly recognize that you are using, for example, an iPhone 14 Pro versus a Samsung Galaxy S23. This identification is critical for provisioning the correct network services.

A crucial point regarding privacy is that the IMEI identifies the device, not the user. The number is assigned during manufacturing and is not inherently linked to a subscriber’s personal information, such as name, address, or phone number.5 The element that identifies the subscriber is the International Mobile Subscriber Identity (IMSI), which is stored on the removable SIM card.4 This distinction is the bedrock of the IMEI system’s power. Because it targets the hardware, it allows carriers to block a specific physical phone from accessing any network, even if a thief inserts a brand-new SIM card. This cooperative security framework, managed by the GSMA (Global System for Mobile Communications), is what makes the IMEI blacklist an effective anti-theft tool across the industry.7

 

IMEI vs. Other Identifiers: A Glossary for the Modern Consumer

 

The mobile landscape is filled with a confusing array of acronyms. Differentiating between them is essential for understanding how your device interacts with a carrier like AT&T.

• IMEI vs. MEID: The primary distinction between an IMEI and a Mobile Equipment Identifier (MEID) lies in the network technology they were designed for. IMEI is the standard for GSM (Global System for Mobile Communications) networks, the technology used by AT&T and T-Mobile in the United States. MEID was the standard for the historically separate CDMA (Code Division Multiple Access) networks used by carriers like Verizon and Sprint.9 Structurally, an IMEI is a 15-digit number, whereas an MEID is a 14-digit number.9 While the technological divide between GSM and CDMA has largely vanished with the universal adoption of 4G LTE and 5G technologies, these identifiers persist. Many modern “world phones” are manufactured with both an IMEI and an MEID to ensure they can be activated on any network.11
• IMEI vs. Serial Number (SN): The difference here is one of scope and purpose. A device’s serial number is an internal identifier used exclusively by the manufacturer (e.g., Apple, Samsung) for its own inventory, warranty, and repair tracking. The IMEI, by contrast, is an external, industry-wide standard used by all carriers for network identification, authentication, and security.3 An AT&T representative will ask for your IMEI, not your serial number.
• IMEI vs. SIM/ICCID: This is a fundamental distinction between hardware and account. The IMEI is permanently hard-coded into the phone’s hardware.4 The SIM (Subscriber Identity Module) card, which is identified by its own unique number called an ICCID (Integrated Circuit Card Identifier), is a small, removable chip that stores your subscriber information, including your phone number and service plan details.4 This separation is what allows you to move your service to a new phone simply by swapping the SIM card.
• IMEI vs. EID: The rise of the eSIM (embedded SIM) has introduced another identifier: the EID, or Embedded Identity Document.14 The EID is the unique serial number for the physical eSIM chip that is soldered onto the phone’s motherboard. This chip can then digitally download a carrier’s SIM profile, which contains the necessary ICCID and IMSI to connect to the network.15 Modern dual-SIM phones often have one IMEI for the physical SIM slot and a second IMEI plus an EID associated with the eSIM functionality.17

To provide a clear reference, the following table summarizes these key identifiers.

Identifier	Full Name	Purpose	Associated With
IMEI	International Mobile Equipment Identity	Uniquely identifies the phone hardware on GSM networks (AT&T, T-Mobile). Used for compatibility checks and blacklisting.	The Phone Itself
MEID	Mobile Equipment Identifier	Uniquely identifies the phone hardware on CDMA networks (Verizon, Sprint).	The Phone Itself
SN	Serial Number	Internal tracking by the manufacturer for warranty and inventory.	The Phone Itself
ICCID	Integrated Circuit Card Identifier	Uniquely identifies the physical SIM card or eSIM profile.	The SIM Card/Profile
IMSI	International Mobile Subscriber Identity	Identifies the subscriber’s account on the network.	The SIM Card/Profile
EID	Embedded Identity Document	Uniquely identifies the eSIM chip embedded in the phone.	The Phone Itself (eSIM)

 

Part 2: The First Step: How to Find Your Device’s IMEI Number

 

Before you can perform any type of check, you must first locate your device’s IMEI. Fortunately, there are several simple and reliable methods to do so.

 

The Universal Method: Using the *#06# Code

 

The fastest and most universally recognized method for retrieving an IMEI on any mobile device is by using a special USSD code. This works on any phone that is powered on and has a functional dialer.5

Instructions:

1. Open your phone’s dialer application, as if you were about to make a phone call.
2. On the keypad, type in the code *#06#.
3. The device’s IMEI number (or numbers) will immediately appear on the screen. There is typically no need to press the “call” button.9

For devices that support both a physical SIM and an eSIM, or have two physical SIM slots, this method will display two distinct IMEI numbers, often labeled as IMEI 1 and IMEI 2.4

 

Locating the IMEI Within Device Settings

 

If you prefer navigating through menus or need to copy the number, you can find the IMEI within the device’s settings.

Step-by-Step Guide for Apple iPhones (iOS):

1. Open the Settings app.
2. Tap on General.
3. Tap on About.
4. Scroll down the page. You will find entries for “IMEI,” “IMEI2” (if applicable), and often “MEID” listed.16 You can press and hold on the number to bring up a “Copy” option, which is useful for pasting it into a web form.22

Step-by-Step Guide for Android Devices (Samsung, Google Pixel, etc.):

1. Open the Settings app.
2. Scroll down and tap on About Phone.
3. On the subsequent screen, you may need to tap on Status or Status information. The IMEI will be listed here.2 The exact path can vary slightly depending on the Android version and manufacturer.

 

Finding the IMEI Physically (When a Device Won’t Power On)

 

In situations where a device is damaged, will not power on, or has been lost or stolen, the physical hardware and its original packaging become crucial sources of information. Knowing these methods is vital when you need to report a stolen phone to AT&T or verify a used device being sold online.

• On the SIM Card Tray: Many modern smartphones, including iPhones from the 6s onward, have the IMEI number finely laser-etched directly onto the physical SIM card tray.12
• On the Back of the Device: Some older iPhone models (like the iPhone 5 and 6) and various Android devices have the IMEI printed in small text on the back of the phone’s casing.19
• Under the Battery: For older phones that feature a removable battery, the IMEI is almost always found on a white sticker located in the battery compartment.3
• On the Original Packaging: If you have retained the original retail box for your phone, the IMEI is always printed on a sticker on the outside, typically alongside the barcodes for the serial number and model number.3 For a lost or stolen device, this is often the only remaining way to retrieve the IMEI.

 

Part 3: Critical Scenarios: Why You Need to Perform an AT&T IMEI Check

 

Running an IMEI check is not just a technical curiosity; it is a necessary step in several high-stakes scenarios involving your mobile device and service with AT&T.

 

Scenario 1: Switching to AT&T with Your Own Device (BYOD)

 

The “Bring Your Own Device” (BYOD) model is popular for its cost savings and flexibility. However, before you can successfully switch to AT&T with a phone you already own, an IMEI check is essential to confirm compatibility.

1. Network Technology Compatibility: AT&T’s network is built on GSM technology. While most modern smartphones are designed to be “world phones” compatible with all network types, some older devices may be CDMA-only and will simply not work on AT&T’s network.24 The IMEI check is the first line of verification for this basic technological compatibility.
2. Frequency Band Support: For a phone to perform optimally and access the full range of services like 4G LTE and 5G, it must support the specific radio frequency bands that AT&T uses. When you enter an IMEI into AT&T’s checker, its system identifies the exact device model and cross-references it against a database of devices known to have the correct hardware for full network support.26
3. Whitelist Verification: Beyond basic compatibility, AT&T maintains an official “whitelist” of devices that are certified to work correctly with all its network features, most importantly VoLTE (Voice over LTE). Following the shutdown of its 3G network, devices not on this whitelist may be blocked from activation, even if they appear to have the right hardware.27 An IMEI check confirms if your device is on this approved list.

 

Scenario 2: Unlocking Your Phone from AT&T

 

A “locked” phone is one that is software-restricted to work only on the network of the carrier that sold it. Unlocking your device grants you the freedom to use it with other carriers, a process that is entirely dependent on the IMEI.

1. Domestic Switching: If you wish to leave AT&T and move to a competitor like T-Mobile or Verizon, your phone must be unlocked first. The entire unlock request and approval process is managed by AT&T using your device’s IMEI as the sole identifier.28
2. International Travel: Using international roaming plans from a US carrier can be prohibitively expensive. An unlocked phone allows you to purchase a cheap, local prepaid SIM card upon arriving in a foreign country, a far more economical option.30
3. Increasing Resale Value: When you decide to sell your old phone, an unlocked device commands a higher price and appeals to a much broader audience of potential buyers, as they are not restricted to using it only on AT&T.31

 

Scenario 3: Navigating the Used Phone Market (Buying or Selling)

 

This is arguably the most critical scenario for performing a comprehensive IMEI check. The used phone market is rife with potential pitfalls, and an IMEI check is your primary tool for due diligence.

1. Blacklist Check: A phone’s IMEI is added to a shared carrier blacklist if it is reported lost or stolen by its original owner. A blacklisted device will be barred from receiving service from AT&T and virtually all other carriers in North America, effectively turning it into a Wi-Fi-only device or “paperweight”.4 An IMEI check is the only reliable way to verify a phone’s blacklist status
   before you hand over your money.
2. Financial Obligation Check: A more subtle but equally damaging risk is purchasing a phone that is still being paid for on an AT&T installment plan. The seller might stop making payments after selling you the phone, at which point AT&T will blacklist the device for non-payment. Furthermore, AT&T has a policy of locking financed devices to the original purchaser’s account, meaning the phone may not work with your AT&T SIM card even if it’s not yet blacklisted.4 A thorough IMEI check from a reputable service can reveal if the device is still under a financing agreement.

 

Scenario 4: Troubleshooting Service and Activation Issues

 

When a seemingly compatible phone fails to work correctly on AT&T’s network, the IMEI is the key to diagnosing and resolving the problem.

1. Incorrect Provisioning: It is common for BYOD devices, especially those not originally sold by AT&T, to be incorrectly provisioned by AT&T’s automated systems. The system might recognize the IMEI but classify it as a more basic device, failing to enable advanced features like 5G, VoLTE, or even 4G LTE, leaving the user with slower H+ speeds.26 Providing the IMEI to an AT&T technical support agent is the first step toward getting the device properly configured in their backend systems.
2. Confirming Identity for Support: For any device-specific problem, from dropped calls to data issues, AT&T support will almost invariably ask for the IMEI. It allows them to pull up the exact hardware profile, its history on their network, and its current provisioning status, which is essential for effective troubleshooting.

 

Part 4: The Official Channels: A Guide to AT&T’s IMEI Tools and Policies

 

AT&T provides several online tools for customers and non-customers to check a device’s status. Understanding how to use these tools and interpret their sometimes-quirky results is key.

 

Using the AT&T BYOD Compatibility Checker

 

This tool is your first stop when considering bringing a device to AT&T’s network.

A Walkthrough of the Online Process:

1. Navigate to AT&T’s official “Bring Your Own Device” (BYOD) webpage.24
2. The page will prompt you to enter the 15-digit IMEI of the device you wish to check.34
3. After you submit the IMEI, the system will analyze it and provide a compatibility result.

Interpreting the Results:

• Compatible: A clear message stating the device is compatible is the ideal outcome. This confirms the device is on AT&T’s whitelist and is approved for activation.
• Not Compatible: This result means the device cannot be used on AT&T’s network. The reason could be technological (e.g., an old CDMA-only phone), a lack of support for required network bands, or simply that AT&T has not certified that specific model for its network.23
• The “Wrong Model Name” Anomaly: A frequent point of confusion is when the AT&T checker confirms an IMEI is compatible but displays an incorrect or unfamiliar phone model name, such as identifying a Nokia phone as an “AT&T Maestro 3”.35 This happens because the system may be referencing internal AT&T development codenames for a device’s hardware profile rather than its public-facing market name. The key takeaway is to focus on the binary result: if the tool gives a “go” signal and allows you to proceed to the next step of purchasing a SIM, the device is almost certainly compatible, regardless of the confusing name displayed. This prevents users from mistakenly concluding a compatible phone is invalid due to a user interface quirk.

 

Using the AT&T Device Unlock Portal

 

This portal is the sole official channel for requesting that an AT&T-locked device be freed for use on other networks.

How to Submit an Unlock Request:

1. Go to the AT&T Device Unlock portal at att.com/deviceunlock.28
2. You will be asked if you are an AT&T customer. You can proceed even if you are not, which is essential for those who have purchased a used AT&T-locked phone.30
3. Enter the device’s IMEI number and follow the prompts.
4. After submission, AT&T will send a confirmation email containing a request number. This is not the approval. You must click the confirmation link within that email within 24 hours to validate your request and keep it active.30
5. AT&T will then review the request against its eligibility criteria. This can take anywhere from a few minutes to 48 hours.30 A final status update will be sent via email or text.

To help decipher the results, the following table explains what each status means and the critical next steps you must take.

 

Status	What It Means	Your Next Steps (Crucial!)
In Progress / Pending	Your request has been received and is under review. AT&T is checking it against their eligibility requirements. 37	Wait. Do not resubmit. This process can take up to 48 hours. Check your email and spam folder for updates.
Approved	Your device is eligible to be unlocked, but the process is not yet complete. AT&T has authorized the unlock. 29	For iPhone: The unlock is processed remotely by Apple’s servers. Insert a non-AT&T SIM card and connect to Wi-Fi to trigger the unlock. A restore via iTunes may be required in rare cases.40	For Android: AT&T will email you an 8-digit unlock code. Insert a non-AT&T SIM card, and the phone will prompt you to enter this code.29
Denied	Your device does not meet AT&T’s unlock eligibility requirements. The denial email will state the reason. 43	Diagnose the reason (e.g., unpaid balance, not active for 60 days, reported stolen). See the Troubleshooting section of this guide for specific steps to resolve the issue. Do not resubmit until the underlying issue is fixed.

 

Crucial AT&T Policies You Must Understand

 

Successfully navigating AT&T’s systems requires understanding their strict policies, which are tied directly to the IMEI.

The Official AT&T Device Unlock Eligibility Requirements:

• Postpaid Accounts: The device must have been used on the AT&T network for at least 60 days. Its installment plan must be fully paid off, with a zero balance. The associated account must be in good standing (not past due), and the device cannot be reported as lost, stolen, or involved in fraud.30
• AT&T Prepaid® Accounts: The device must have a history of at least six months of paid service on AT&T Prepaid.29
• Business Accounts: Requirements are similar to postpaid but may also include the completion of a service contract and explicit permission from the controlling company to unlock the device.30

A critical policy that impacts the used market is AT&T’s practice of “account locking” in addition to “network locking.” A standard network lock prevents a phone from being used on a competitor’s network. However, AT&T also locks devices with active installment plans to the specific AT&T account that is financing it.33 This means that even if you are an AT&T customer, you cannot use a phone purchased from another AT&T customer if that phone still has a payment balance. It will be blocked from your account. This makes it absolutely essential for buyers of used AT&T phones to verify not just the network lock status, but also the financial status tied to the IMEI.

 

Part 5: Third-Party IMEI Checkers: An Independent Analysis

 

While AT&T’s official tools are necessary for certain tasks, third-party services fill a crucial information gap, particularly for buyers in the secondary market.

 

Why and When to Consider a Third-Party Service

 

The primary reason to use a third-party IMEI checker is for comprehensive due diligence before purchasing a used phone. Official carrier tools are designed to serve their own customers and network needs; they may not provide information about a device’s history on other carriers or its financial status if you are not the original owner.32

Reputable third-party services query multiple databases simultaneously, including the global GSMA blacklist shared by carriers worldwide. They can often provide a single, consolidated report detailing a phone’s blacklist status, financial obligations, original carrier, current SIM lock status, and even iCloud Find My iPhone lock status—information that is impossible to gather from a single carrier tool.8

 

A Comparative Review of Leading Services

 

• IMEI.info (formerly IMEpro): This is a long-standing service in the market, frequently mentioned in online forums.46 It offers a tiered approach with free basic checks that provide device model information, and paid premium services that deliver detailed reports on carrier lock, blacklist status, and warranty information.50 It also offers pricing packages for wholesale and small business users who need to check many devices.53
• Phonecheck: This service has established itself as an industry-standard certification tool for the used device resale and recycling market.48 Its credibility stems from its adoption by businesses that rely on its accuracy for their operations.55 Phonecheck provides comprehensive Device History Reports that specifically look for blacklist status, hidden financial locks, and carrier eligibility, which are the biggest risks when buying a used phone.7
• Other Services: A multitude of other websites and apps offer IMEI checks. User reviews are mixed; some are reliable, while others are ad-heavy, provide inaccurate information, or are fronts for questionable unlocking services.56 Caution is advised when using lesser-known tools.

The following table compares the capabilities of AT&T’s official tools against what a typical comprehensive third-party service offers.

Feature Check	Official AT&T Tools	Typical Third-Party Service (e.g., Phonecheck, IMEI.info)
Cost	Free	Free (basic) to Paid (comprehensive reports)
AT&T BYOD Compatibility	Yes	Sometimes (less reliable than official tool)
AT&T Unlock Status	Yes (for your own requests)	Yes (can check current lock status)
Global Blacklist Status (GSMA)	No (only checks AT&T’s list)	Yes (this is a key feature)
Financial Obligation / Installment Plan Check	Yes (via denial reason on unlock portal)	Yes (often a premium, critical feature)
Original Carrier Identification	N/A	Yes (can tell you if a phone is from Verizon, T-Mobile, etc.)
iCloud / MDM Lock Status	No	Yes (some services offer this)
Best Use Case	Activating on AT&T, Unlocking from AT&T	Vetting a used phone before purchase

 

A Word of Caution: Unlocking Services vs. Checking Services

 

It is vital to distinguish between legitimate IMEI checking services and often-fraudulent third-party unlocking services. While a checking service provides information, an unlocking service claims to perform the unlock itself. However, only the original carrier—in this case, AT&T—can legitimately authorize the unlocking of a device tied to its network.59 Third-party unlocking sites often take a customer’s money and either fail to deliver or use unauthorized methods that could cause further issues.57 Always use AT&T’s official portal for the unlock process itself. Use reputable third-party services for information gathering and due diligence only.

 

Part 6: Troubleshooting Common AT&T IMEI-Related Issues

 

Navigating IMEI-related problems with AT&T can be frustrating. This section provides solutions to the most common issues users face.

 

Problem: “My unlock request was denied.”

 

Step 1: Read the Denial Reason. The email from AT&T is not generic; it will specify why the request was denied.43

Step 2: Take Action Based on the Reason:

• “Unpaid balance linked to your device”: This is the most frequent denial reason.44 The device’s installment plan must be paid off completely. If you are the original owner, you can do this through your myAT&T account portal.61 If you purchased the phone used, you have likely bought a financed device, and your options are extremely limited as you cannot pay off another person’s account.32
• “Device hasn’t been active for at least 60 days”: This is a firm policy for postpaid accounts. There is no workaround; you must wait until the 60-day period has elapsed since the device was first activated on the network.30
• “Device is reported as lost or stolen”: If you are the legitimate owner and believe this is an error, you must contact AT&T’s fraud department to investigate and clear the report.63 If you bought the phone used, it is almost certainly a blacklisted device.
• “No longer active on an AT&T account”: This is a common, and often erroneous, denial message, particularly for non-customers or for devices that have been inactive for a while.36 The first step is to carefully resubmit the request, ensuring you select “No” when asked if you have an AT&T mobile number. If the denial persists, the issue may require manual intervention from an AT&T support representative. As a final resort for a legitimately owned and paid-off device, filing a complaint with the FCC can often compel a resolution.36

 

Problem: “I bought a used phone that is blacklisted or still on an installment plan.”

 

In this unfortunate situation, your recourse is almost exclusively with the person or entity that sold you the device, not with AT&T. AT&T’s contractual and financial obligation is to the original account holder, not to a third-party buyer.

Actionable Steps:

1. Contact the Seller Immediately: Provide the seller with the report from your third-party IMEI check as proof and demand a full refund.7
2. Use Marketplace Protections: If you made the purchase through a platform like eBay, Swappa, or PayPal, immediately initiate their buyer protection or dispute resolution process.
3. Legal Action: For an uncooperative private seller, filing a case in small claims court may be a viable last resort.7
4. What You Cannot Do: You cannot force AT&T to remove a valid blacklist report placed by the original owner. You also cannot access or pay off the installment plan on someone else’s account.32

 

Problem: “My compatible, unlocked phone isn’t getting full service on AT&T (e.g., no VoLTE/5G).”

 

This issue is typically caused by incorrect IMEI provisioning in AT&T’s backend systems, a common occurrence with BYOD devices that were not originally sold by AT&T.26

The Solution:

1. Contact AT&T’s technical support department (dialing 611 from an AT&T phone is a direct route).
2. Clearly state the problem. For example: “My device is a [Your Phone Model], and it is on AT&T’s approved BYOD list. However, I am not receiving VoLTE or 5G service. I believe the IMEI needs to be provisioned correctly for full network features.”
3. The support agent may need to manually update your IMEI in their billing and network systems to match a profile of a device that is fully capable of LTE and 5G services. This can sometimes require an escalation to a more senior technical support tier.26

 

Part 7: Expert Recommendations and Final Checklists

 

The IMEI is the central point of control for a device’s life on a cellular network. By using it proactively, consumers can protect themselves and ensure a smooth experience. The following checklists synthesize this report’s findings into actionable steps.

 

Pre-Purchase Checklist for Buying a Used Phone

 

• [ ] Insist on the IMEI: Always obtain the IMEI from the seller before any money changes hands. A seller’s refusal to provide it is an immediate and major red flag.7
• [ ] Run a Third-Party Check: Use a comprehensive, reputable third-party checking service (like Phonecheck or a premium IMEI.info report) to verify:

• [ ] Blacklist Status: Ensure it is not reported lost or stolen.
• [ ] Financial Status: Confirm it is not on an active installment plan.
• [ ] Carrier Lock Status: Verify if it is unlocked or locked to a specific carrier.

• [ ] Cross-Reference with AT&T: If the device is advertised as being for AT&T, run the IMEI through the AT&T unlock portal. A denial due to an unpaid balance is a definitive deal-breaker.
• [ ] Use Protected Platforms: Whenever possible, make purchases through platforms like eBay or Swappa that offer robust buyer protection policies.

 

Pre-Switch Checklist for Bringing Your Own Device to AT&T

 

• [ ] Confirm it’s Unlocked: Contact your current carrier to ensure your device has been unlocked from their network.
• [ ] Check AT&T Compatibility: Run the device’s IMEI through AT&T’s official BYOD compatibility checker.24
• [ ] Interpret Results Wisely: If the checker confirms compatibility but shows an unusual device name, it is likely safe to proceed.35
• [ ] Don’t Cancel Early: To avoid losing your phone number, do not cancel your service with your old carrier until your new AT&T service is fully activated and tested.24
• [ ] Backup Your Data: Before you swap SIM cards or activate an eSIM, perform a full backup of your device’s data.24

 

Pre-Request Checklist for Unlocking Your AT&T Device

 

• [ ] Verify Eligibility: Review AT&T’s unlock requirements for your specific account type (Postpaid, Prepaid, Business) to ensure you meet them.30
• [ ] Check Installment Balance: Log in to your myAT&T account and confirm that the installment plan balance for the device is $0.61
• [ ] Check Account Status: Ensure your overall AT&T bill is not past due.
• [ ] Have the IMEI Ready: Have the correct 15-digit IMEI for the device you wish to unlock.

 

A Look Ahead: The Role of eSIM and EID

 

The industry’s gradual shift away from physical SIM cards to embedded eSIMs streamlines the process of switching carriers. An eSIM allows a user to download a new carrier profile digitally without needing to physically swap a card. However, this technological convenience does not alter the fundamental power structures controlled by the IMEI. The device’s hardware (identified by its IMEI) is still what gets locked to a network, what gets blacklisted for theft, and what gets tied to a financial agreement. The EID identifies the chip that holds the digital SIM, but the IMEI remains the ultimate identifier for the device itself. Therefore, all the principles of checking for compatibility, lock status, and financial obligations remain just as critical in the age of the eSIM as they were with physical SIMs.

 

Sources:

www.thalesgroup.com, Accessed on July 10, 2025, [https://www.thalesgroup.com/en/markets/digital-identity-and-security/inspired/basics-of-phone-security/imei-number#:~:text=The%20IMEI%20(International%20Mobile%20Equipment,all%20valid%20mobile%20phone%20equipment](https://www.thalesgroup.com/en/markets/digital-identity-and-security/inspired/basics-of-phone-security/imei-number#:~:text=The%20IMEI%20(International%20Mobile%20Equipment,all%20valid%20mobile%20phone%20equipment). What is an IMEI number? | AT&T, Accessed on July 10, 2025, https://www.att.com/wireless/what-is-imei-number/ What is an IMEI number & what is it used for | Mint Mobile, Accessed on July 10, 2025, https://www.mintmobile.com/blog/what-is-imei-number/ What’s in a Number? The Essential Guide to IMEI | Gophermods, Accessed on July 10, 2025, https://www.gophermods.com/whats-in-a-number-the-essential-guide-to-imei/ What is an IMEI number and what is it for? | Thales Group, Accessed on July 10, 2025, https://www.thalesgroup.com/en/markets/digital-identity-and-security/inspired/basics-of-phone-security/imei-number International Mobile Equipment Identity – Wikipedia, Accessed on July 10, 2025, https://en.wikipedia.org/wiki/International_Mobile_Equipment_Identity What is a Blacklisted Phone? – – Phonecheck, Accessed on July 10, 2025, https://www.phonecheck.com/blog/what-is-a-blacklisted-phone IMEI Blacklist Status Check, Accessed on July 10, 2025, https://imei.org/check-imei/blacklist What’s The Difference Between MEID vs IMEI? | by Holly Zink …, Accessed on July 10, 2025, https://medium.com/safeguarde/whats-the-difference-between-meid-vs-imei-9ab31c5f1092 IMEI vs. MEID – News, Accessed on July 10, 2025, https://www.imei.info/news/imei-vs-meid/ What are IMEI, MEID, and SN, and how to check them? – HONOR, Accessed on July 10, 2025, https://www.honor.com/global/support/content/en-us15807013/ Find the serial number, EID, or IMEI on your iPhone, iPad, or iPod touch – Apple Support, Accessed on July 10, 2025, https://support.apple.com/en-us/108037 IMEI DMEI ICCID UDID UUID eSIM Every Thing You May Not Know About Your – ByteSIM, Accessed on July 10, 2025, https://bytesim.com/blogs/esim/imei-dmei-iccid-udid-uuid-esim-every-thing-you-may-not-know-about-your-mobile-device! MG52/E eSIM Activation Guide – Cisco Meraki Documentation, Accessed on July 10, 2025, https://documentation.meraki.com/MG/eSIM/eSIM_Activation_Guide MEID vs EID vs IMEI vs ICCID : r/ATT – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/medcnl/meid_vs_eid_vs_imei_vs_iccid/ Apple iPhone 12 – Find IMEI, Serial Number, & Dual SIM – AT&T, Accessed on July 10, 2025, https://www.att.com/device-support/article/wireless/KM1361199/Apple/iPhone12 How to find your IMEI number on iOS devices | Verizon Support, Accessed on July 10, 2025, https://www.verizon.com/support/how-to-find-imei-ios-video/ How to find your IMEI number on Android devices | Verizon Support, Accessed on July 10, 2025, https://www.verizon.com/support/how-to-find-imei-android-video/ How do I find the IMEI, model number and serial number for a Samsung Galaxy phone?, Accessed on July 10, 2025, https://www.samsung.com/ie/support/mobile-devices/how-do-i-find-the-imei-model-number-and-serial-number-for-samsung-galaxy-device/ 9 Ways to Find the IMEI Number on Your iPhone or iPad – MakeUseOf, Accessed on July 10, 2025, https://www.makeuseof.com/ways-to-find-the-imei-number-on-iphone-ipad/ What is an IMEI Number and Why is it Important? – MTX Connect Helpdesk, Accessed on July 10, 2025, https://faq.mtxc.eu/en-us/article/what-is-an-imei-number-and-why-is-it-important-16rl2pv/ support.apple.com, Accessed on July 10, 2025, https://support.apple.com/en-us/108037#:~:text=Go%20to%20Settings%20%3E%20General%20and,hold%20the%20number%20to%20copy. Bring Your Own Device – Consumer Cellular, Accessed on July 10, 2025, https://www.consumercellular.com/shopping/details/sim How to Bring Your Phone or Device to AT&T | AT&T Wireless, Accessed on July 10, 2025, https://www.att.com/wireless/how-to-bring-your-own-device/ Bring Your Own Device (BYOD) or Phone (BYOP) | AT&T Wireless, Accessed on July 10, 2025, https://www.att.com/wireless/byod/ AT&T IMEI Issue Resolved??? – OnePlus Community, Accessed on July 10, 2025, https://community.oneplus.com/thread/66875 AT&T Kills Online IMEI Check Tool – Now No Official Way to Check Device Stolen or Compatibility via IMEI : r/ATT – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/p0t2wg/att_kills_online_imei_check_tool_now_no_official/ Check Phone or Device Unlock Status – AT&T, Accessed on July 10, 2025, https://www.att.com/deviceunlock/status What is AT&T Unlock Status? How to Check or Troubleshoot? – DirectUnlocks, Accessed on July 10, 2025, https://directunlocks.com/articles/att-unlock-status Get Info About Device Unlock Eligibility – AT&T Wireless Customer Support, Accessed on July 10, 2025, https://www.att.com/support/article/wireless/KM1008728/ Selling Your AT&T Phone Before It’s Paid Off, Accessed on July 10, 2025, https://sell.techreboot.co/blog/selling-your-at-t-phone-before-it-s-paid-off Checking balance in financed phone : r/ATT – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/17ugvd3/checking_balance_in_financed_phone/ AT&T Unpaid Devices on Installment Plans Now Locked to Account, Accessed on July 10, 2025, https://www.rvmobileinternet.com/att-devices-on-installment-plans-now-locked-to-accounts/ Let’s identify your device – AT&T, Accessed on July 10, 2025, https://www.att.com/buy/prepaid-byod/ Is AT&T really checking IMEIs? : r/dumbphones – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/dumbphones/comments/18veens/is_att_really_checking_imeis/ I’ve tried to unlock my phone but it keeps getting denied. Please help!! : r/ATT – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/1gpp8va/ive_tried_to_unlock_my_phone_but_it_keeps_getting/ SIM Unlock : r/ATT – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/ym8jli/sim_unlock/ AT&T Unlock Failure after 7 days of waiting : r/surfaceduo – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/surfaceduo/comments/nkrqh7/att_unlock_failure_after_7_days_of_waiting/ “Check your unlock status Current status – Approved We’ve approved your request to unlock your device. ” Does this mean it’s unlocked now or I have to wait for some other confirmation? : r/ATT – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/19bo38e/check_your_unlock_status_current_status_approved/ after i ve received my approval from at&t… – Apple Communities, Accessed on July 10, 2025, https://discussions.apple.com/thread/5893342 Device unlock approved.. what next? : r/ATT – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/740o5x/device_unlock_approved_what_next/ AT&T Device Unlock Instructions, Accessed on July 10, 2025, https://www.att.com/idpassets/support/pdf/ATTDeviceUnlockCodeInstructions.pdf SIM LOCK ? Unlock your Android & iPhone at the same time for FREE – YouTube, Accessed on July 10, 2025, https://www.youtube.com/watch?v=72XcAFB2YC8 Looks like the IMEI number you entered doesn’t match an AT&T device Try entering it again Dial *#06# – YouTube, Accessed on July 10, 2025, https://www.youtube.com/watch?v=s1bony3ZPNs When you finance a phone, is the financing tied to the account or the phone’s IMEI? : r/ATT, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/1ibx02q/when_you_finance_a_phone_is_the_financing_tied_to/ Reliable ESN Checker for AT&T? : r/mobilerepair – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/mobilerepair/comments/9xxgah/reliable_esn_checker_for_att/ AT&T IMEI Check, Accessed on July 10, 2025, https://imei.org/check-imei/att Device History Report – Phonecheck, Accessed on July 10, 2025, https://www.phonecheck.com/imei-checker Best website to use when checking IMEI : r/mobilerepair – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/mobilerepair/comments/anbpys/best_website_to_use_when_checking_imei/ IMEI Checking – IMEI.info, Accessed on July 10, 2025, https://www.imei.info/imei-checker/ IMEI.info: IMEI Check – Free online service, Accessed on July 10, 2025, https://www.imei.info/ IMEI iPhone Check, Accessed on July 10, 2025, https://www.imei.info/imei-iphone-check/ Pricing | IMEI.org, Accessed on July 10, 2025, https://imei.org/pricing Phonecheck | ERP Gold Solutions | Texas, Accessed on July 10, 2025, https://www.erp.gold/phonecheck/ PhoneCheck Testimonials | Real User Reviews & Feedback, Accessed on July 10, 2025, https://www.phonecheck.com/testimonials Mobile Imei Status Checker App – Apps on Google Play, Accessed on July 10, 2025, https://play.google.com/store/apps/details?id=com.sim.imei.status.checker Network Unlock App for ATT – Apps on Google Play, Accessed on July 10, 2025, https://play.google.com/store/apps/details?id=com.att.unlock.code.device.unlock.app How to Do an IMEI Check and Determine Phone Compatibility – WhistleOut, Accessed on July 10, 2025, https://www.whistleout.com/CellPhones/Guides/IMEI-Check IMEI number blacklisted by another company as “revenge”? – Apple Communities, Accessed on July 10, 2025, https://discussions.apple.com/thread/5843837 stuck with att financed phone – my options? (HELP) : r/NoContract – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/NoContract/comments/1hnr3ug/stuck_with_att_financed_phone_my_options_help/ Check Your Installment Agreement Details – AT&T Wireless Customer Support, Accessed on July 10, 2025, https://www.att.com/support/article/wireless/KM1044993/ Learn About Smartphone Installment Plans – AT&T Wireless Customer Support, Accessed on July 10, 2025, https://www.att.com/support/article/wireless/KM1106686/ IMEI blacklisted : r/ATT – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/1dpxcb8/imei_blacklisted/ Your unlock request was denied because your phone is no longer active on an AT&T account : r/ATT – Reddit, Accessed on July 10, 2025, https://www.reddit.com/r/ATT/comments/10e0g5l/your_unlock_request_was_denied_because_your_phone/ What Is a Blacklisted Phone? What Does It Mean & What To Do – BankMyCell, Accessed on July 10, 2025, https://www.bankmycell.com/blog/what-is-a-blacklisted-phone/