Credit check - How to check credit of SIM card?

The credit could be easily checked over USSD command directly on the module. Connect to the gateway by using HyperTerminal or Putty and send at command at&gXX=XTDussd, where XX stands for number of GSM module and ussd for the command.

Example: you want to check credit on GSM module g08 and the command is *101#. You will enter following at&g08=XTD*101#