AT Command For Overwriting ICCID Sim

Question

Is it possible to overwrite a SIM card's ICCID number using AT commands? If so, what is the command for it?

If not possible via AT commands, is there another way to overwrite the ICCID of a sim card? USSD etc

Answer 1

No, I'm afraid it is not possible.

ICCID number is physically written in the internal memory of the SIM itself.
As soon as the cellular modem/telephone is powered on:

• the SIM is resetted
• the ATR string is read (ATR = Answer To reset)
• the communication modem <-> SIM is configured

After that the SIM is just like some sort of "data array", in which you can read specific data at specific indexes. One of them is ICCID number and it is used for the SIM authentication on the network.

Whay it is not possible to change it? Well SIM stands for " S ubscriber I dentity M odule". Changing your ICCID number would mean adulterating its identity, and that would fail to fulfil SIM's own main purpose.