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James David Thorburn

Tax Attorney at Greenwood Village, CO

5.0   5 reviews

also known as Jim Thorburn

  • Licensed for 32 years
    State CO
    Acquired 1991
    Active No misconduct found

We have not found any instances of professional misconduct for this lawyer.

About James

Learn James’s areas of practice.

Practice areas
  1. Tax
    Cannabis Tax Law Including 280E Issues

  2. Real estate
    Real Estate and Probate/Estate Planning, Short Sales

  3. Construction and development

  4. Land use and zoning
    We have notable cases for land use and zoning.

Jim is a preeminent lawyer and a formidable force in the cannabis industry.  

Jim obtained the first Supreme Court opinion regarding the cannabis federalism dispute in Standing Akimbo v. United States on June 28, 2021. It was a Statement by Justice Clarence Thomas, cautioning that the Controlled Substances Act is likely unconstitutional as to state-legal cannabis. The press notes that Justice Thomas' Statement represents a "seismic shift" away from the legitimacy of federal cannabis prohibition. As a result of Jim's work and dedication "legalization is near".

Through his advocacy, obtaining "costs of goods sold" is now a constitutional right.  Slowly but surely Jim has eroded the force of Section 280E.  His continued advocacy has been a driving force in the success of cannabis business. 

Jim provides cost-effective legal representation for business. The focus of our practice is in the following areas:

  • Federal, State and Local Cannabis Tax Law and Tax Controversy
  • Regulatory and Licensing of Cannabis Business
  • Litigation - emphasizing tax controvery, commercial litigation, in federal and state courts - emphasis in federal practice
  • Appeals - extensive experience in both federal and state appellate courts- emphasis in federal practice
  • Real Estate, Construction, and Land Use

Photos and videos

Jim, by invitation, speaking to the Ohio Legislature when Ohio was considering the passage of its medical cannabis law


Thorburn Law Group LLC
5460 South Quebec Street
Suite 310
Greenwood Village, CO, 80111

Tax lawyers nearby


5.0 / 5.0
  5 customer reviews
5 Star
4 Star
3 Star
2 Star
1 Star
Posted by anonymous | July 3, 2019
This review is from a person who hired this attorney.
| Hired Attorney
Business Tax Work
I had Jim do some tax work for our business. He did a really good job. Was always in communication with us. I definitely recommend him.
Posted by Steve | December 8, 2015
This review is from a person who hired this attorney.
| Hired Attorney
Call Jim Thorburn for Quick, Compassionate and Effective action
Jim Thorburn has helped us with family; Court related and DMV matters, as well as and numerous calls for advice. We found Jim to be personally engaged with our case and their outcomes, assuring that we achieved our legal goals. Jim and his growing team have a deep understanding of Colorado and Federal laws and great insight as to how the individual can stay within them and still win their cases. I would highly recommend Jim Thorburn and Thorburn Law. Thanks!
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Posted by Jeff | October 22, 2015
This review is from a person who hired this attorney.
| Hired Attorney
All-around good experience
We used Mr. Thorburn's services to prepare our wills and power of attorney documents. Fortunately were able to make an appointment in just a short period of time. Our meeting with Mr. Thorburn started right on time. Everyone was very compassionate, professional and knowledgeable. He answered all of our questions and explained things with just the right amount of detail. He and his team are very efficient, and we were finished in less than two hours. I will use his practice for any future legal needs. I will recommend and have already recommended him to friends.
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Posted by anonymous | September 14, 2015
This review is from a person who hired this attorney.
| Hired Attorney
Jim Thorburn Review
Jim Thorburn is an extremely intelligent attorney. He is also very kind. He handled my case with precision and care and most importantly, I trusted him throughout the process. He delivered the results I was looking for and went above and beyond. I would recommend him to any potential client who asked.
Posted by John | August 26, 2015
This review is from a person who hired this attorney.
| Hired Attorney
Excellent counsel multiple times
I've used James Thorburn numerous time, from setting up a business to navigating various legal scenarios while running a business, and even personal matters involving an HOA. While Jim does specialize in Real Estate and Construction, he is quite adept and knowledgeable about law in general, and has always been able t assist me, answer my questions, and take the necessary action to resolve the matter at hand. Jim is responsive, trustworthy, and competent. I wouldn't hesitate to use him again, or to recommend his services.
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  • Free Consultation 30 minutes
Payment methods
Cash, Check, Credit Card


AVVO RATING 8.5 (Excellent)

Work Experience

  • Managing Partner
  • Thorburn & Walker, LLC,
  • 2015 - Present
  • Attorney
  • Law Office of James D Thorburn
  • 2009 - 2015
  • Attorney
  • Campbell Killin Brittan & Ray, LLC
  • 2007 - 2009
  • Managing Partner
  • Thorburn & Walker, LLC,
  • 1996 - 2007
View all work experience


  • University of Denver College of Law
  • JD - Juris Doctor
  • 1991
  • California State University, Northridge
  • BS - Bachelor of Science
  • 1987

Sample of Legal Cases

  • Feinberg v. Commissioner
  • We are pleased to have received the 1st positive court decision on section 280E, which we believe will benefit the cannabis industry. In re Feinberg, 2015 U.S. App. LEXIS 22161 (10th Cir. Dec. 18, 2015)


  • Colorado Bar Association
  • Member
  • N/A
  • Douglas/Elbert Bar Association
  • Member
  • N/A
  • Elizabeth Chamber of Commerce
  • President
  • 1997 - 2004

Languages Spoken

  • English

Honors and Awards

  • Top Legal Speaker- Winter Meeting
  • BridgeWest Network
  • 2015
  • Who's Who
  • National Registry of Who's who
  • 2003
  • Who's Who
  • Strathmore's Who's Who Worldwide
  • 2002
  • Mensa
  • Mensa
  • 1991
  • Excellence Award-Civil Procedure
  • American Jurisprudence Award
  • 1989
View all awards


Speaking Engagements

  • MIG Summit
  • Tax Law and Business Law
  • 2016
  • NCIA Legal Symposium
  • Cannabis Law and 280E
  • 2015
  • MIG Symposium
  • Effects of 280E on Business Owners
  • 2015
  • BridgeWest Network Winter Meeting
  • 5th Amendment Issues ref: 280E
  • 2015
  • ICA Winter Conference- NYC
  • Section 280E Tax Law
  • 2014
View all speaking engagements

Attorney endorsements

Received (5)
Given (2)
Endorse James
Unknown Attorney | Jan 15
Relationship: Worked for lawyer
"James Thorburn is an excellent attorney with 30 years of experience. He brings a vast amount of knowledge and experience to the table that cannot be found elsewhere. James has numerous repeat clients who have been very pleased with him and whose trust he has earned. He consistently achieves excellence at what he does and is very trustworthy. James has a great personality and is very friendly, yet he has a way of dominating a court room. I would highly recommend Jim for all areas of law that he practices."
Business Attorney | Jan 15
Relationship: Worked for lawyer
"I have worked for Jim Thorburn since 2017 and he has been an inspiration to work with. Jim is passionate about his clients, his profession, and his community. Jim effectively communicates with clients during their most stressful times and is always striving to provide a solution to their problems. Jim takes the time to understand the legal challenges his clients face and their impact on his clients’ lives, enabling him to find innovative and creative resolutions to their legal issues. His goal is to achieve the best possible results for his clients, while tackling their issues quickly and efficiently. I highly recommend Jim Thorburn as an attorney."
Litigation Attorney | Nov 01
Relationship: Fellow lawyer in community
"I have known Jim for years. He is an excellent lawyer, a tenacious advocate, and a professional with the highest integrity."
Tax Attorney | Apr 12
Relationship: Fellow lawyer in community
"I endorse this lawyer. Solid analytical skills and a creative litigator."
Litigation Attorney | Apr 05
Relationship: Fellow lawyer in community
"I endorse Jim. He is a passionate advocate for his clients. He works hard to understand each client's unique needs and to develop a high level of knowledge about the legal issues particular to them."
Administrative law