Prepare to fork out a higher service charge if you wish to pay your credit card bill by cash. HDFC Bank, the largest issuer of credit cards in the country, has decided to double its service charge for making cash payments at its branches or automated teller machines (ATMs).

"Dear HDFC Bank credit card member, fee for cash payment made at HDFC Bank branches or ATMs will be revised to Rs 100 effective November 1, 2012," the private lender alerted its clients recently via text messages and e-mails.

The bank currently charges Rs 50 as cash processing fee.

Sources confirmed that the service charge will be hiked in November but added that the bank has kept other charges related to credit card transactions unchanged. They also pointed out that the bank is only the latest private player to increase its charges as other large private and foreign lenders have already raised credit card transaction fees in recent months.

ICICI Bank and Citibank also charges Rs 100 if customers deposit cash at their branches to repay credit card bill.

Bankers said this practice is aimed to encourage customers in using the online services offered by bank. "These are small transactions and should be done via net banking or other online services. We want the customers to become savvy," said a senior official with a private bank who did not wish to be named.

Earlier this year large private lenders in the country had increased the service charges on their savings accounts that included penalties for inoperative accounts, cash deposits over a certain amount in bank branches, and fee on mobile transfers.