Jon Tonsing has practiced law in California for over forty years. He joined Einwechter & Hyatt in May 2021, expanding the firm's business and real estate practice.

Jon was previously a partner in the Walnut Creek, California law firm of Tonsing & Tonsing and the California law firm of Archer Norris, where he practiced from 1992-2018. For quite a few years, in addition to his duties as partner with Archer Norris, a firm with five offices that employed about 120 attorneys in its heyday, Jon acted as its corporate counsel. From 2018-2021 he was of counsel to the Walnut Creek, California firm Horner Law Group.   

Jon has provided quality representation in a variety of business, real estate, commercial, contract, bankruptcy, and employment related matters. He has represented California financial institutions, prime contractors, subcontractors, developers, suppliers, employers, real estate brokers and salespeople, real estate appraisers, tax professionals, investors, property owners, and entrepreneurs in both litigation and the preparation of contracts, partnership agreements, and real estate documentation. One of Jon's most memorable cases is Lambert v. Carneghi (2008) 158 Cal. App. 4th 1120, a case where he prevailed on behalf of his real estate appraiser client in both the trial court and the California State Court of Appeal.

A graduate with honors from St. Mary's College of California, Jon earned a B.A. degree in classical liberal arts in 1980, and received his J.D. from Hastings College of the Law in 1983. Jon is admitted to practice before the United States Supreme Court, federal trial and appellate courts, the United States Tax Court, the United States Claims Court, and all the courts of the State of California. Since his admission to the California State Bar in 1983, Jon has been primarily engaged in civil litigation and administrative proceedings, with experience in real estate, business, and construction litigation and transactions, civil appellate practice, professional liability defense, and employment issues.  

Jon is also the President of a California nonprofit public benefit corporation, Trevor’s Eagle Blanket Foundation. Since its inception in 2010, the Foundation has donated over 5,000 fleece tie blankets to the patients of Children’s Hospital Oakland in memory of Jon’s son, Trevor, and in furtherance of the Eagle Scout leadership project Trevor had started. Jon served on the Yuba County Grand Jury from 2018-2020, acting as foreperson during the last year. He has volunteered with the California Grand Jurors’ Association since 2020, training hundreds of grand jurors throughout the State of California.