IMEI
Definition
International Mobile Equipment Identity, a 15-digit identifier of the handset hardware. Format is 8-digit TAC + 6-digit serial + 1-digit Luhn check. Identifies the device, not the SIM.
- Length
- 15 digits
- What it identifies
- The physical handset device, not the subscriber or SIM card
- Display command
- *#06# on the phone
Common questions
What does IMEI tell you about a phone?+
IMEI identifies the handset hardware itself, not the SIM card or carrier. It's a 15-digit number burned into the baseband and stays with the device across different networks and SIM swaps. Knowing the IMEI lets you track which physical phone was used, not who owns it.
How do you find an IMEI during an investigation?+
Dial *#06# on the phone and the IMEI displays on screen. IMEI also appears in every call detail record (CDR) logged by the carrier. This gives you confirmation from both the device side and the network side.
How is an IMEI structured?+
The 15-digit IMEI breaks into three parts: 8 digits (Type Allocation Code, which identifies the manufacturer and model), 6 digits (serial number of that specific handset), and 1 check digit calculated using the Luhn algorithm to catch transcription errors.
Related terms
- ICCID
- Integrated Circuit Card Identifier. The serial number of the physical SIM card itself, stored in EF_ICCID. It identifies the card as a...
- IMSI
- International Mobile Subscriber Identity. A 15-digit number stored in EF_IMSI on the SIM that uniquely identifies the subscriber account on the mobile...
- CDR
- Call Detail Record. Telco-side log of A-party, B-party, start time, duration, IMEI, IMSI and serving cell ID. Lawful-intercept output under the IT...
- Chip-Off
- NIST SP 800-101 R1 Level 5 acquisition. Desoldering the NAND or eMMC chip from the PCB and reading it directly with a...
- EPC / 5GC
- Evolved Packet Core (LTE) and 5G Core (5G NR), the all-IP packet cores that replaced the circuit-switched GSM core. 5GC is service-based,...
- Faraday Bag
- A signal-blocking pouch with conductive mesh lining that prevents cellular, Wi-Fi, Bluetooth and NFC signals from reaching a seized phone. The standard...
- FDE
- Full Disk Encryption. Default on modern Android (file-based encryption since Nougat) and iOS. Encryption keys are tied to the user passcode and...
- Ki
- The 128-bit secret authentication key stored on the SIM and in the operator's Authentication Centre (AuC). Never leaves either party in cleartext...
- MSC
- Mobile Switching Centre, the GSM core node that routes calls and SMS between the cellular network and the PSTN, and queries the...
- MSISDN
- Mobile Station International Subscriber Directory Number. The dialable phone number. Stored on the HLR, not always on the SIM.
Explained in these topics
- Mobile Phone Forensics: Acquisition and ExaminationInternational Mobile Equipment Identity. 15-digit unique identifier burned into the handset baseband. Dial *#06# to display. Logged in every CDR.
- Mobile Technologies: 2G to 5G, GSM/CDMA, SIM and IMEIInternational Mobile Equipment Identity, a 15-digit identifier of the handset hardware. Format is 8-digit TAC + 6-digit serial + 1-digit Luhn check. Identifies...