Rainier Legal Center

31615 Third Ave.,
P.O. Box 100
Black Diamond, WA 98010

(425) 432-3380


14205 SE 36th St.,
Suite 100
Bellevue, WA 98006

(425) 492-0066

McWS Law Inc.

19200 Von Karman Ave.,
Suite 400
Irvine, CA 92612

(714) 465-8008

John M. McWilliams

John M. McWilliams

John M. McWilliams

(888) 550-7656

Email John M. McWilliams ›

Accounting Beginnings

McWS Law is managed by its founder and owner, John M. McWilliams, a dual-credentialed Attorney-CPA, who began his career as a Certified Public Accountant (“CPA”) in California at a Big 4 Accounting Firm and has held various management positions at several large public companies. After practicing as a CPA for a decade, he returned to law school, while still actively practicing as a CPA, and obtained his law degree and subsequently his Tax LL.M. and began practicing tax law.

Legal Credentials

John is currently licensed to practice law in California and Washington and is also an active CPA in both these states. He is admitted to practice before the United States Tax Court, all Courts in California and Washington State, as well as the United States District Courts for the Northern, Central, Eastern and Southern Districts of California. John represents clients before the United States Tax Court, Office of Appeals and various courts in California and Washington. As Corporate Counsel for businesses in various locations, he advises on corporate governance matters and protects his clients from liability by assisting on matters pertaining to tax and regulatory compliance and disclosures, including domestic and international tax reporting requirements.

Current Practice and Academic Work

John serves on the Corporate and Business Tax Committee for the State Bar of California. He is also a member of the tax, estate, trust and probate sections of the Orange County Bar Association and a member of the American Bar Association. He also belongs to the American Association of Attorney-Certified Public Accountants and the California Society of CPAs. In addition, John is actively expanding his activities to include committees in King County, Washington, due to the recent expansion and growth of his Seattle law practice in 2017.

John serves as an Adjunct Professor at California State University – Fullerton where he teaches federal tax planning, federal tax procedures and business entities for the Graduate Masters in Taxation Program. Recently, he was selected to advise and update the tax curriculum program courses and text content at Colorado State University. This includes drafting, revising and publishing updated course teaching materials for its Graduate Tax Program.

As an Attorney, CPA and Tax Professor, John continues to lead his law firm, McWS Law, applying the principals of both professions and staying abreast of current issues and problems within the tax practice.

Admission Details

  • Admitted in U.S. District Court, Central, Eastern, Northern and Southern Districts of California
  • U.S. Court of Appeals, Ninth Circuit
  • U.S. Tax Court
  • 2007, California
  • 2011, Washington State

Law School Attended

  • Southwestern University School of Law, Class of 2006, J.D.
  • Loyola Law School, Class of 2009, LL.M., Taxation

University Attended

  • Ohio State University, B.S.