Regular savings bank accounts require customers to maintain a certain average monthly balance (AMB). Top banks such as State Bank of India (SBI), HDFC Bank and ICICI Bank have fixed their monthly average balance requirements. The requirements depend on the location of a customer's account in urban, metro, semi-urban and rural areas. Banks also charge a penalty from customers who fail to maintain an average monthly balance in their savings account. The penalty varies according to various factors such as the location of branch.