Doug Sigel

Practice Group Leader for: Sales & Use and Income Tax


Doug Sigel has 25 years of experience trying and settling disputes in hearings and courts across the nation. His practice focuses on state and local taxation, especially litigation at the administrative, trial, and appellate levels. Examples of the types of matters Doug handles include: sales and use tax, state corporate income tax (including the Texas margin tax), Texas property tax, motor vehicle sales tax, oil and gas severance tax, insurance tax, motor fuels tax, mixed beverage tax, unclaimed property, tax credits/incentives, nexus disputes, audits, hearings, trials and appeals, tax collection cases, voluntary disclosure agreements, letter rulings, and open records requests.


Doug handles his large docket of administrative, district court, and appeals cases in an aggressive yet efficient matter and always seeks the best outcome possible for his clients. Doug strives to streamline the resolution of his cases through innovative approaches to each of his cases. This usually involves gaining a thorough understanding of the issues, personalities, and facts early in a dispute and crafting a strategy to achieve an expedited settlement of the dispute through a collaborative interaction with counsel for the taxing authority. If necessary, Doug will take the case to trial as quickly as possible and leverage the strengths of the taxpayer’s position and evidence to present the taxpayer’s argument in a focused and creative manner.


Doug has spoken on a variety of sales and use and income tax topics at seminars sponsored by IPT, COST, TEI, The Hartman Forum, the Texas Society of CPAs, the Tulane Tax Institute, the State Bar of Texas, the National Association of State Bar Tax Sections, and the ABA Tax Section. He is also a frequent author on state and local tax topics. For example, Doug has authored a chapter for the IPT Income Tax Deskbook published in 2012. He is on the executive board of the state and local tax committee of the ABA tax section. He is IPT’s overall chair for sales tax. He was the chair of the 2014 IPT Sales and Use Tax Symposium and is on the planning committee for the 2015 ABA/IPT Sales Tax Seminar. He is the chair of the National Association of State Bar Tax Sections.

Practice Group Leader, Ryan Law Firm LLP, Austin Office
Partner, Scott Douglas & McConnico, LLP, Austin
Debate Coach, Dartmouth College, Hanover, New Hampshire



  • Successfully represented several hundred taxpayers over a span of two decades in sales and use tax, income/franchise, insurance, oil and gas severance, mixed beverage, and motor fuels tax cases at the administrative, trial, or appellate levels.
  • Successfully litigated numerous cases involving the Texas sale-for-resale exemption or the manufacturing exemption and obtained hundreds of millions of dollars of refunds in those cases. For example, Doug (1) obtained dozens of large sales tax refunds for defense contractors of tax paid on items charged to federal contracts after successfully litigating those issues in the Raytheon and Health Care Service Corporation cases listed below, (2) obtained a refund of tax paid on purchase of electrical transportation and distribution equipment after successfully litigating the issue in the El Paso Electric case listed below, and (3) obtained refunds of tax paid and hotel’s purchases of consumables used by guests after successfully litigating the issue in the DTWC case listed below.
  • Currently litigating two manufacturing exemption cases in Texas courts.
  • Handled dozens of audits and administrative hearing. For example, Doug eliminated through settlement a $5 million tax collected not remitted assessment by the Texas Comptroller against a large construction contractor.
  • Successfully defended numerous taxpayers in numerous nexus cases involving sales tax or franchise tax.
  • Successfully defended tax collection cases at the administrative and trial court levels.
  • Handled several cases involving complex procedural issues such as statutes of limitations defenses, second refund claim issues, pleas to the jurisdictions regarding exhaustion of administrative remedies, challenges to Texas Comptroller refund claim rules, and interpretation and enforcement of managed audit and settlement agreements.
  • Handled cases in states of Texas, New York, California, Illinois, Florida, Georgia, Maryland, Ohio, Pennsylvania, New Jersey, Missouri, New Mexico, Minnesota, Arkansas, Tennessee, Louisiana, Washington, Nevada, and Nebraska.
  • Handled many appeals at Court of Appeals and Supreme Court level in numerous states.

Institute for Professionals in Taxation (IPT)
American Bar Association Tax Section, Executive Board of the State and Local Tax Committee
Austin Bar Association
Public Service
Counsel to Texas Ambulance Association for over 15 years

State and Local Tax Litigation
Federal Tax Litigation
Commercial Litigation
Oil & Gas Litigation

J.D., University of Texas School of Law, 1989

  • Notes Editor, Texas Law Review

B.S., Northwestern University, 1985


"Traps for the Unwary in Dealing with the Major Business Taxes - Income, Gross Receipts and Margin Taxes", ABA/IPT Advance Income Tax Seminar, March, 2015.
"Economic Substance, Sham Transactions", ABA/IPT Advance Sales/Use Tax Seminar, March, 2015
“How Are the Economic Substance Doctrine and Related Principles Being Applied in State Tax Cases?”, ABA Section of Taxation State Tax Committee, January, 2015.
“Current Developments for May 2014 through August 2014”, ABA Tax Section State & Local Tax Committee, September, 2014.
“Update on Texas Margin Tax: Decisions Affecting the Cost of Good Sold Deduction”, IPT Tax Report, September, 2014.
“Defining Value: How Far Can the Texas Legislature Constitutionally Go?”, 28th Annual Legal Seminar on Ad Valorem Taxation, August, 2014.
“Manufacturing Exemptions and Incentives across Tax Types SUT, FT (COGS and Tax Rate), Property Tax, and More”, TSCPA 2014 State Taxation Conference, August, 2014.
“Oil and Gas Update: New Developments and Issues”, TEI State and Local Roundtable, June, 2014.
“Current Developments in Sales and Use Taxation”, 2014 IPT 38th Annual Conference, June, 2014.
“District court Rules Texas Taxpayers Cannot Elect to Use Three-Factor MTC Apportionment in Lieu of Texas’ Single-Factor Apportionment”, IPT Tax Report, March, 2014.
“Successful Litigation Strategies”, ABA/IPT Advanced Income Tax Seminar, March, 2014.
“Update on Other Business Taxes (Ohio, Washington, and Texas)”, ABA/IPT Advanced Income Tax Seminar, March, 2014.
“Property Tax Issues West of the Mississippi”, 2014 COST Property Tax Workshop, January, 2014.
“Current Developments/Hot Topic in Exemptions from Sales/Use Taxes”, 20th Annual Paul J. Hartman State and Local Tax Forum, October, 2013.
“Sourcing for State Sales Tax and Income Apportionment”, National Association of State Bar Tax Sections 34th Annual Meeting, October, 2013.
“Plain Meaning or Ambiguity: What Did the Judges Say - and What Does it Mean for Texas Taxpayers?,” TSCPA 2013 Texas State Taxation Conference, August, 2013
“Update on Texas Court Cases Involving the Sale-for-Resale Exemption”, IPT Tax Report, July, 2013.
“Sales Tax Implications of the Integrated Plant Theory,” 2013 IPT 37th Annual Conference, June, 2013.
“Is it Possible to Get Uniformity in Property Taxation?,” 2013 COST Property Tax Workshop, January, 2013.
“Top 10 Sales Tax Cases of 2012,” 2012 Paul J. Hartman State and Local Tax Forum, November, 2012.
“Nexus Update on the 20th Anniversary of the Quill Decision,” 2012 Advanced Sales and Use Tax Academy, November, 2012.
“National Trends/Updates in State and Local Taxation,” 61st Tulane Tax Institute Program Schedule, October, 2012.
“Oh No, They Didn’t: Procedural Roadblocks in Obtaining Refunds,” National Association of State Bar Tax Sections 33rd Annual Meeting, October, 2012.
“Pitfalls and Planning Opportunities,” TSCPA 2013 State Taxation Conference, August, 2012.
“Cutting Edge Issues Regarding Manufacturing Exemptions from Sales and Use Taxes,” ABA Tax Section State & Local Tax Committee, September, 2012.
“Economic Substance and Business Purpose in State Taxation: Current Judicial and Statutory Trends,” IPT Annual Conference, June, 2012.
“Recent Texas Sales and Use Tax Cases,” IPT Tax Report, May, 2012.
“Emerging Issues—Cases in the Pipeline,” ABA/IPT Advanced Income Tax Seminar, March, 2012.
“Update on Constitutional Litigation Regarding the Texas Margin Tax,” IPT Tax Report, December, 2011.
“The ‘Other’ Business Taxes—Michigan, Ohio, and Texas,” IPT Income Tax Symposium, November, 2011.
“Texas Supreme Court Case Involving Apportionment of Geophysical and Seismic Data,” IPT Tax Report, July, 2011.
“Sales and Use Tax Aspects of Government Contracting,” ABA Tax Section May Meeting, May, 2011.
“Recent Court Case Involving the Texas Sale-For Resale Exemption,” IPT Tax Report, April, 2011.
“Using TPP to Provide Services—What is Taxable and What is Not?; Bundled vs. Mixed Transactions,” ABA/IPT Advanced Income Tax Seminar, March, 2011.
“Update on Court Cases Involving the Texas Manufacturing Exemption,” IPT Tax Report, January, 2011.
“Voluntary Disclosure—Don’t Get Hit By a Big Stick When You Go After the Carrot,” Advanced Sales and Use Tax Academy, November, 2010.


  • Combs, et al. v. Checkfree Services Corp., Cause No. 14-15-0027-CV, in the Fourteenth Court of Appeals.
  • American Multi-Cinema, Inc. v. Combs, et al., Cause No. 03-14-00397-CV, In the Third Court of Appeals.
  • Combs, et al. v. Fair Isaac Corporation, Cause No. 03-14-00124-CV, In the Third Court of Appeals.
  • Allstate Insurance Company v. Combs et al., Cause No. 03-13-00341-CV, In the Third Court of Appeals.
  • Southwest Royalties, Inc. v. Combs et al., Cause No. 03-12-00511-CV, In the Third Court of Appeals.
  • MidCon Compression, L.L.C., v. Reeves County Appraisal District, Cause No. 08-13-00322-CV, In the Eighth Court of Appeals.
  • AETC II Privatized Housing, L.L.C., v. Tom Green County Appraisal District, Cause No. 03-13-00463-CV, In the Third Court of Appeals.
  • Combs, et al. v. Ryan, L.L.C., Cause No. 03-13-00400-CV, In the Third Court of Appeals.
  • Combs, et al. v. Imperial Fire and Casualty Insurance Company, Cause No. 03-13-00576-CV, In the Third Court of Appeals.
  • EMC Corporation, v. Hegar, et al., Cause No. 03-15-00113-CV, In the Third Court of Appeals.


  • Southwest Royalties, Inc. v. Combs, et al., Cause No. 14-0743, in the Supreme Court of Texas.
  • Hallmark Marketing Company, LLC v. Combs, et al., Cause No. 14-1075, in the Supreme Court of Texas.


  • Gulf Chemical and Metallurgical Corporation v. Combs et al., No. 03-12-00772-CV, Tex. App. -Austin, March 26, 2015.
  • Hallmark Marketing Company, LLC v. Combs, et al., 2014 WL 6090574, Tex. App. – Corpus Cristi, November 13, 2014.
  • Combs, et al. v. Health Care Services Corp., 401 S.W. 3d 623, Texas Supreme Court, June 7, 2013.
  • Leoncito Plant, L.L.C., v. Combs, et al., WL 1460195, Tex. App.—Amarillo, April 4, 2013.
  • DTWC Corp. v. Combs, et al., 400 S.W. 3d 149, Tex. App. – Austin, April 11, 2013.
  • Verizon Business Network Services, Inc. v. Combs, et al., 203 WL 1343530, Tex. App. – Amarillo, April 3, 2013.
  • In re The State of Texas, No. 03-12-00370-CV, 2012 Tex. App. LEXIS 7558 (Tex. App.—Austin, Aug. 30, 2012, no pet.).
  • Combs, et al. v. Health Care Service Corp., 2011 WL 2652141, Tex. App.—Austin, July 7, 2011.
  • State v. BFI Waste Services of Texas, LP, 2011 WL 1086585, Tex. App.—Austin March 23, 2011.
  • Combs, et al. v. Health Care Service Corp., 2011 WL 1005419, Tex. App.—Austin, March 16, 2011.
  • Combs, et al. v. Frito Lay, Inc., 2011 No. 03-11-00157-CV. Tex. App. March 14, 2011.
  • Bell Helicopter Textron, Inc. v. Combs, et al., 2011 WL 6938491, Tex. App. – Austin. December 29, 2011.
  • Alcoa World Alumina, L.L.C. Ark.94, 377 S.W.3d 164, February 25, 2010.
  • Combs, et al. v. El Paso Elec. Co., 2010 WL 4910052, Tex. App.—Austin, December 01, 2010.
  • GTE Southwest Inc. v. Combs, et al., 2010 WL 2218662, Tex. App.—Austin, June 3, 2010.
  • Combs, et al. v. Chevron, Inc., 319 S.W.3d 836, 2010 WL 1404670, Tex. App.—Austin, April 09, 2010.
  • Reynolds Metals Co. v. Combs, et al., 2009 WL 961615 Tex. App.—Austin, April 8, 2009.
  • Southwestern Bell Yellow Pages v. Combs, et al., 2009 WL 211633, Tex. App.—Austin, January 30, 2009.
  • Goodyear Tire & Rubber Co. v. State, 275 Neb. 594, 748 N.W.2d 42, 2008 WL 1947576, Neb., May 2, 2008.
  • Af-Cap, Inc. v. Republic of Congo, 220 Fed. Apprx. 343 (5th Cir. 2007).
  • In the Matters of the Protest of Support Terminals Operating Partnership, 2006 WL 1806400, N.M. TaxRw. Dept., 2006.
  • El Paso Natural Gas Co. v. Strayhorn, 208 S.W.3d 676, 2006 WL 2975309, 167 Oil & Gas Rep. 648, Tex. App.—Texarkana, October 18, 2006.
  • Af-Cap, Inc. v. Republic of Congo, 462 F.3d 417 (5th Cir 2006).
  • Tyson Fresh Meats, Inc. v. State, 270 Neb. 535, 704 N.W.2d 788, 2005 WL 2675662, Neb. — October 21, 2005.
  • Local Neon Co., Inc. v. Strayhorn, 2005 WL 1412171, Tex. App.—Austin, June 16, 2005.
  • Walker Int’l Holdings, Ltd. v. Republic of Congo, 415F.3d.413 (5th Cir. 2005).
  • Strayhorn v. Willow Creek Resources, Inc., 161 S.W.3d 716, 2005 WL 670537, Tex. App.—Austin, March 24, 2005.
  • May Dept. Stores Co. v. Strayhorn, 2004 WL 1898244, Tex. App.—Austin, August 26, 2004.
  • Strayhorn v. Raytheon E-Systems, Inc., 101 S.W.3d 558, 2003 WL 192105, Tex. App.—Austin, January 30, 2003.
  • Sergeant Enterprises, Inc., v. Strayhorn. No. 03-03-00047-CV. Tex. App. —January 17, 2003.
  • B.F. Goodrich W. v. McCorkle, 865 S.W.2d 618 (App.-Houston [14th Dist.] 1999).

State Bar of Texas
United States Tax Court
United States Court of Appeals for the Fifth Circuit
United States District Court – Eastern District of Texas
United States District Court – Southern District of Texas
United States District Court – Western District of Texas