Bharti Cellular, in collaboration with ICICI Bank and VISA, has launched the "mChq" service, which enables Airtel subscribers and ICICI Bank's VISA cardholders to pay for purchases through their mobile phones. Airtel subscribers can get a new 128K SIM card, which is free of cost for the first three months, while ICICI Bank cardholders will be issued an add-on card on the basis of their existing ICICI Bank VISA credit card. Airtel subscribers will have to pay normal SMS charges for sending, receiving and confirming the transaction for a monthly charge of Rs 10 (waived for the first three months). Once the product is bought, the retailer sends an SMS to the customer from a special mobile phone indicating the amount. The customer then enters his PIN number and sends back an SMS to the retailer acknowledging the amount to be paid. Both parties get a confirmatory SMS indicating completion of the transaction.