What is a SIM and what does it identify?¶

A SIM is a removable card or embedded profile through which a mobile network recognises and authenticates a subscription. It links network service to a device at a time; it does not identify the human user.

Preserve the subscription identifiers¶

Record the SIM or eSIM condition, device found with it, ICCID, IMSI, associated number, provider and dates. Establish whether it was active, suspended, replaced or moved.

Provider records can show which handset identifiers used the subscription and when. A SIM can be transferred between devices, while replacement can continue the same number on a new profile.

Separate subscription, device and person¶

The subscriber may differ from the person possessing or operating the SIM. Later seizure does not prove earlier use.

Compare provider associations with device artefacts, possession, location and communications. Preserve original field names and explain discrepancies as possible timing, replacement or collection differences before resolving them.

IMSI and ICCID identify the subscription and SIM profile at different technical layers.