Business Description

Westamerica Bancorporation is a bank holding company registered under the Bank Holding Company Act of 1956, as amended (“BHCA”). Its legal headquarters are located at 1108 Fifth Avenue, San Rafael, California 94901. Its principal administrative offices are located at 4550 Mangels Boulevard, Fairfield, California 94534, its telephone number is (707) 863-6000 and its website address is www.westamerica.com. The Company provides a full range of banking services to individual and commercial customers in Northern and Central California through its subsidiary bank, Westamerica Bank (the “Bank”). The Bank is a California-chartered commercial bank whose deposits are insured by the Federal Deposit Insurance Corporation (the “FDIC”) up to applicable limits. The principal communities served are located in Northern and Central California, from Mendocino, Lake and Nevada Counties in the north to Kern County in the south. The Company’s strategic focus is on the banking needs of small businesses. In addition, the Bank owns 100% of the capital stock of Community Banker Services Corporation (“CBSC”), a company engaged in providing the Company and its subsidiaries with data processing services and other support functions. -2- The Company was incorporated under the laws of the State of California in 1972 as “Independent Bankshares Corporation” pursuant to a plan of reorganization among three previously unaffiliated Northern California banks. The Company operated as a multi-bank holding company until mid-1983, at which time the then six subsidiary banks were merged into a single bank named Westamerica Bank and the name of the holding company was changed to Westamerica Bancorporation. The Company acquired five banks within its immediate market area during the early to mid 1990’s. In April 1997, the Company acquired ValliCorp Holdings, Inc., parent company of ValliWide Bank, the largest independent bank holding company headquartered in Central California. Under the terms of all of the merger agreements, the Company issued shares of its common stock in exchange for all of the outstanding shares of the acquired institutions. The subsidiary banks acquired were merged with and into the Bank. During the period 2000 through 2005, the Company acquired three additional banks. In 2009 and 2010, the Bank acquired the banking operations of two failed banks, the former County Bank and Sonoma Valley Bank, from the Federal Deposit Insurance Corporation (“FDIC”). At December 31, 2025, the Company had consolidated assets of approximately $6.0 billion, deposits of approximately $4.8 billion and shareholders’ equity of approximately $934 million. The Company assesses and is careful to address potential health, safety, and environmental risks. The Company cares for the environment and works to mitigate pollution and the potential risks related to climate change by implementing practices such as recycling and reusing materials, and controlling energy usage. The Company’s Annual Report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and any amendments to those reports as well as beneficial ownership reports on Forms 3, 4 and 5 are available through the SEC’s website (https://www.sec.gov). Such documents as well as the Company’s director, officer and employee Code of Conduct and Ethics are also available free of charge from the Company by request to: Westamerica Bancorporation Corporate Secretary A-2M Post Office Box 1200 Suisun City, California 94585-1200