Airtel Lanka Limited is a subsidiary of Bharti Airtel Limited. It is the third largest mobile operator in the world. Airtel recharge (Airtel Topup) can be done as follows.
You can enter USSD Code *567#<PIN number in the card># and press call to recharge your Airtel prepaid account. More Useful USSD codes for Dialog, Mobitel , Hutch , Airtel and Etisalat can be found here.