A valid ICCID is a 19 digit number.
It goes like this:
- 2 digits: 89 (always 89).
- 2 digits: CC = Country Code (i.e. 61 = Australia, 86 = China,..)
- 2 digits: II = Issuer Identifier (AAPT = 14, EZI-PhoneCard = 88, Hutchison = 06, Optus = 02/12/21/23, Telstra = 01, Telstra Business = 00/61/62, Vodafone = 03...)
- 12 digits (sim number, just try).
- 1 digit. Checksum number. It is calculated with the Luhn algorithm. Input the 18 digit prefix here and get the last digit:
https://planetcalc.com/2464/
Good luck ...