Westamerica Bancorporation operates as the bank holding company for Westamerica Bank that provides a range of banking services to corporate and individual customers. Its deposit products include retail savings and checking accounts; non interest bearing demand deposits; interest bearing transaction, savings, and time deposits; and certificates of deposit. The company's loan portfolio comprises commercial and residential real estate loans, commercial loans, construction loans, and consumer and other installment loans. It operates through 95 branch offices in 21 counties in northern and central California. The company was formerly known as Independent Bankshares Corporation and changed its name to Westamerica Bancorporation in 1983. Westamerica Bancorporation was founded in 1972 and is headquartered in San Rafael, California.