Sumitomo Mitsui Banking Corporation (SMBC, 三井住友銀行) and its group companies offer a broad range of financial services centered on banking. They are also engaged in the leasing, securities, credit card, investment, mortgage securitization, venture capital and other credit related businesses. The following lists the activities of SMBC, its subsidiaries and affiliates in the various business segments. SMBC is a member of Sumitomo Mitsui Financial Group, Inc.

The headquarters and branches, including overseas branches, of SMBC engage in deposit taking, lending, securities brokering and trading, securities investment, money transfer, foreign currency exchange, corporate bond trustee services and custody services, financial futures underwriting, investment trust sales and other commercial banking activities.