Canadian · Validation

ICCID decoder and check digit.

Checks whether an ICCID (the 18-22 digit number printed on a SIM card) is well-formed, by verifying its Luhn check digit, and reads the country field. Runs entirely in your browser: nothing you type is transmitted anywhere.

Sources: ITU-T E.118, Luhn per ISO/IEC 7812, country codes per ITU-T E.164 Format check only — cannot confirm a SIM is active or whose it is

Inputs

Result

Enter an ICCID and press Validate.

How an ICCID is built

The ICCID (Integrated Circuit Card Identifier) is the serial number of a SIM card or eSIM profile. ITU-T E.118 defines it as an ISO/IEC 7812 primary account number: a 2-digit 89 (the telecommunications industry identifier), a country code based on ITU-T E.164, an issuer identifier of 1–4 digits, the issuer's account number, and a final check digit. ISO/IEC 7812 allows up to 19 digits; SIMs in use are typically 19 or 20 digits including the check digit.

The check digit is the Luhn algorithm (ISO/IEC 7812-1 Annex B) run over every earlier digit: starting with the digit just left of the check digit and moving left, double every second digit (subtract 9 if it goes over 9), add everything up, and the check digit makes the total a multiple of 10 — the same formula used for IMEI and payment cards.

The country field is 2 or 3 digits. Countries in the North American numbering plan other than Canada print 01 (a zero before +1), Canada prints 302, Russia prints 701 and Kazakhstan prints 997 (both +7). Everything else uses the plain E.164 calling code, for example 44 for the UK or 882 for international networks. This tool reports the calling code only. It does not name a carrier, because issuer allocations are not published as an open list.

Sources: ITU-T E.118; SIM card § ICCID (Wikipedia), which summarises E.118, ISO/IEC 7812 and the country-field conventions; Luhn algorithm (Wikipedia); calling codes from the libphonenumber metadata cross-checked with the list of country calling codes.

What this tool does and doesn’t check

A passing checksum only proves the digits are internally consistent, a well-formed ICCID. It does not mean the SIM was ever issued, is active, or belongs to anyone, and this tool cannot look any of that up. An ICCID is semi-sensitive: with other details it can help someone attempt a SIM swap or account lookup, so avoid posting it publicly. Everything here runs entirely in your browser: nothing you type is transmitted, stored, or logged.