How to convert the last letter of IOT card?

The mobile IOT card number is a set of 5 digits on the back of the SIM chip, and the sum of 4 sets of digits and letters is the SIM card number. To know the attribution of this Internet of Things card, you can query the corresponding number 1 1 or 13 according to the SIM card. IoT cards support 2G/3G/4G networks, and users can apply to the three major operators of China Mobile, China Unicom and China Telecom or professional IoT platforms according to their own needs. Unlike the SIM card, the IOT card can check the phone number. IOT card is mainly identified by ICCID card number, and the 20-digit ICCID card number can be seen on the back of the card case or SIM card. When the official WeChat account is recharged, it can be solved by ICCID card number.