Old Second Bancorp operates as a bank holding company for Old Second National Bank that provides a range of banking services. The Company accepts deposits and offers lending of various types. In addition, it provides safe deposit services, trust services, wealth management services, foreign currency, direct deposits, debit and credit cards, and other services, as well as acquires the U.S. treasury notes and bonds. Further, the Company offers online and mobile banking, corporate cash management products, automated tax payments, automatic teller machines access, telephone banking, lockbox accounts, wire transfers, and vault services for currency and coin. It also provides investment, agency, and custodial services for individual, corporate, and not-for-profit clients.