MSISDN
Definition
Mobile Station International Subscriber Directory Number. The dialable phone number. Stored on the HLR, not always on the SIM.
- Full name
- Mobile Station International Subscriber Directory Number
- What it is
- The dialable phone number
- Stored on
- HLR
- Not always on
- The SIM itself
Common questions
Why can't investigators always read the MSISDN directly off a seized SIM?+
The MSISDN is a network-assigned identifier stored primarily in the carrier's HLR database rather than hard-coded on the SIM, so while many SIMs do store the number, extraction tools cannot guarantee it is present and investigators often need a lawful carrier record request to confirm it.
How does the MSISDN differ from the IMSI?+
The IMSI is a fixed identifier tied to the SIM itself and used internally by the network for authentication, while the MSISDN is the externally dialable phone number associated with that subscription; the two are linked in carrier records but are not the same identifier.
Why does MSISDN matter in call detail record analysis?+
Call detail records are indexed by MSISDN, so it is the key value investigators use to request, filter, and correlate a specific subscriber's call and message history from a carrier, including when a number has been ported or reassigned.
Related terms
- 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...
- 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...
- ICCID
- Integrated Circuit Card Identifier. The serial number of the physical SIM card itself, stored in EF_ICCID. It identifies the card as a...
- IMEI
- International Mobile Equipment Identity, a 15-digit identifier of the handset hardware. Format is 8-digit TAC + 6-digit serial + 1-digit Luhn check....
- 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...