William Hadden Zimmerling

William Hadden Zimmerling

Denver, Colorado

William Zimmerling has over fifteen years of lending and collections experience as an officer with major banks such as Chemical Bank (now part of JPMorgan Chase), First Interstate, and Wells Fargo. His practice focuses on collections, creditor rights, contract disputes, and civil litigation.

After leaving banking, he spent six years as an Executive Officer with facility based telecommunications and Internet companies. During that time he was the president for five years of a USA Swimming Team, Foothills Swim Team.

Over the next five years Mr. Zimmerling worked with major Broker Dealers and FDIC Insured Institutions to build and launch deposit programs and deposit facilities. These programs collectively totaled many billions of dollars including a $10 billion deposit program for A.G. Edwards & Sons, Inc. and a $2 billion deposit facility for Bank of America.

Mr. Zimmerling attended the United States Coast Guard Academy in New London, Connecticut and is a graduate of Trinity College in Hartford Connecticut and Rutgers School of Law in Newark New Jersey. At Trinity he was a member of the Alpha Delta Phi Fraternity and a member of the Trinity College Crew where he won a National Championship with an undefeated boat and later rowed in the Henley Royal Regatta. While at Rutgers Law School, Mr. Zimmerling spent two terms working for the Constitutional Litigation Clinic.


He is admitted to the Connecticut State Bar, the Colorado State Bar, and the U.S. District Court for Colorado. Mr. Zimmerling served as a law clerk to the Honorable John W. Madden IV in the Denver District Court.

Areas of Practice

  • Collections
  • Contract Disputes
  • Entrepreneur Law
  • Contracts
  • Banking & Finance Law
  • Business & Commercial Law
  • Debtor/Creditor
  • Foreclosure & Alternatives
  • Divorce
  • Mergers & Acquisitions

Litigation Percentage

  • 75% of Practice Devoted to Litigation

Bar Admissions

  • Connecticut, 1987
  • Colorado, 2010
  • U.S. District Court District of Colorado, 2010


  • Rutgers, The State University of New Jersey School of Law - Newark, Newark, New Jersey
    • J.D. - 1987
  • University of Denver College of Law, Denver, Colorado
    • Graduate Law Studies - 2010
    • Honors: Renewable Energy and Project Finance-Scholastic Excellence Award
  • Trinity College, Hartford, Connecticut
    • B.A. - 1980


  • Presenter, Nuts & Bolts of Collection Law, LawReviewCle, 2012

Professional Associations and Memberships

  • Colorado Bar Association, 2009 - Present
  • American Bar Association, 1985 - Present

Ancillary Businesses

  • Business Advisory
  • Asset Purchases


  • Alpha Delta Phi