Transparency notes
Methodology, sources and catalog changelog
Random IMEI creates synthetic identifiers for offline QA and educational examples. This page explains exactly what the tool verifies, what its TAC snapshot can and cannot establish, and when that snapshot last changed.
Current catalog snapshot
- Version
- 2025-11-02
- Device profiles
- 60
- Distinct TAC prefixes
- 128
Versioned internal legacy fixture snapshot with no established original provenance or reuse license; device labels require primary-source verification, otherwise consumers fall back to format and Luhn only.
For automated tests, download the CC0 Luhn vectors or read the complete developer contract and catalog limitations. The legacy TAC mapping snapshot is not offered as a public dataset because its original provenance and reuse license are not established.
How a result is built
- The selected profile supplies one eight-digit prefix from the versioned local snapshot.
- The server adds a cryptographically generated six-digit testing serial.
- The fifteenth digit is calculated with the Luhn formula used for IMEI check digits.
- The service rejects repeats inside the current batch and returns at most 50 rows.
Passing Luhn proves only that the number is structurally valid. It does not prove that a device exists, that a TAC-to-model mapping is current, or that a number is absent from carrier and GSMA systems.
TAC data scope
The bundled mappings are a legacy internal fixture set migrated from earlier application code. Their original upstream provenance and reuse license are not established, so Random IMEI does not publish the raw mappings as a reusable dataset. Current labels remain explicitly unverified and are not sent to the browser validator, which performs no device attribution.
Random IMEI is not affiliated with or endorsed by GSMA, does not redistribute the licensed GSMA Device Database, and does not claim real-time, complete, or authoritative coverage.
A generated serial can theoretically coincide with an assigned device identifier. Use outputs only as synthetic fixture data in isolated test environments; never submit them to carrier, activation, warranty, financing, insurance, blacklist, or production identity systems.
Primary technical references
- GSMA IMEI Database overview — the three IMEI parts and GSMA TAC allocation role.
- GSMA TS.06 IMEI Allocation and Approval Process — current allocation principles, duplication prevention and security requirements.
- GSMA security FAQ — concise definitions of TAC and IMEI.
What the validator checks
The validator normalizes the input, distinguishes a completable 14-digit body from a complete 15-digit IMEI, and calculates or checks the Luhn digit entirely in the browser. It extracts the first eight digits as the TAC field but does not compare them with the internal generator snapshot or attribute a manufacturer or model. It does not query GSMA, a carrier, a blocklist, a manufacturer, warranty records, ownership records, or live device status.
Changelog
- 2026-08-05 — Canonicalization and provenance boundary. Consolidated generator TAC data in one versioned server-only snapshot, made every legacy mapping explicitly unverified, removed catalog lookup from browser validation, and published only the independently authored CC0 Luhn vectors as reusable data.
- 2026-07-18 — Transparency revision. Published this methodology, clarified collision and coverage limitations, and aligned site claims with the actual 50-row server-side generator. No TAC mappings were added in this revision.
- 2025-11-02 — Catalog snapshot. Last recorded change to the server-side device/TAC catalog.
Corrections
To report an incorrect mapping or documentation issue, email support@randomimei.com. Include the affected profile and a link to a reliable source. Reports are reviewed manually; submission does not guarantee inclusion.