SIM, eSIM and handset identifiers: a privacy-oriented reference table (IMSI, SUCI, ICCID, EID, IMEI), November 2026

A small reference table of the identifiers involved when a phone with a SIM or eSIM registers on a mobile network: IMSI, SUPI, SUCI, TMSI, 5G-GUTI, ICCID, EID, IMEI, IMEISV, MSISDN and the Ki authentication key. For each identifier the CSV gives its length and structure, its check-digit algorithm (Luhn, ISO/IEC 7064 MOD 97-10 or none), whether it normally goes over the radio interface, the defining standard (3GPP TS 23.003, TS 33.501, ITU-T E.212, E.118 and E.164, GSMA SGP.22 and SGP.29, ETSI TS 102 221) and a one-line note on what it reveals about the user. The table is meant to separate three layers that privacy discussions about "anonymous" or "encrypted" SIMs often blur: the subscription (IMSI/SUPI/SUCI, Ki, MSISDN), the card or chip (ICCID, EID) and the handset (IMEI). Changing one layer does not change the others. For example, a new SIM in the same phone still reports the same IMEI, and 5G SUCI only conceals the IMSI on standalone 5G networks where the operator has provisioned a non-null protection scheme. The lengths are standard maximums or typical values, and operators vary. This is a reference for understanding privacy trade-offs, not guidance for avoiding lawful identification requirements.