HomeServices OverviewTax Services for Foreign SellersNexus Reviews & Voluntary Disclosure ServicesRegistration & Filing Services
About PrietoDion ConsultingUS Sales Tax for Foreign Sellers BlogInternet Sales Tax & Economic Nexus BlogMassachusetts Tax Blog

PrietoDion Consulting Partners LLC
              Tax Consultants for the U.S. and International (non-U.S.) Businesses              

PrietoDion Consulting Partners is a Tax Advisory Firm specializing in advising and assisting U.S. and non-U.S. Businesses with Understanding and Managing their Multi-State Tax Obligations.  We provide our State & Local Tax (SALT) advisory services to businesses located throughout the United States and in Europe, Canada, Australia, New Zealand, Mexico and Asia. 

PrietoDion Consulting Partners LLC was founded and is managed by Sylvia Dion, CPAPrior to launching PrietoDion Consulting Partners, LLC, Sylvia's 25+ years of professional tax experience include holding SALT Senior Management and Leadership positions with Ernst & Young (EY) and Grant Thornton, including serving as the New England Area Director of Employment Tax Services for EY.  In addition to her public accounting experience, Sylvia has also worked in the corporate tax departments of several high-tech, software and manufacturing companies. Currently, Sylvia specializes in providing tax consulting and compliance services to U.S. businesses as well as to businesses in many parts of the world. 

In addition to providing tax consulting services and solutions, Sylvia is a speaker, writer and avid tax blogger. Her articles on SALT issues and developments have been published in the Journal of AccountancyJournal of State TaxationJournal of Multistate Taxation and IncentivesJournal of Practical US/Domestic Tax StrategiesBloomberg BNA Tax Management Multistate Tax ReportBloomberg BNA Weekly State Tax ReportTax-Analysts State Tax Notes, and Institute for Professionals in Taxation (IPT) Tax Report. Sylvia is also the author of the "Minding Massachusetts" column published quarterly in Tax Analysts - State Tax Notes. She also frequently presents to executive and industry groups and on practitioner webcasts and has been quoted in several news reports and articles, including in Bloomberg BusinessWeek, the Boston Globe,, NPR and other media.

Sylvia is also regarded as an authority on state tax nexus issues, Economic Nexus development, state "Amazon Laws" and Federal "Internet Sales Tax" legislation.  As a Massachusetts based practitioner, Sylvia is also regarded as a subject matter expert and top adviser on Massachusetts tax issues. Her writing and blogging efforts have also focused on Massachusetts tax developments, including authoring articles and blogs on significant Massachusetts tax developments, such as the enactment and repeal of the Massachusetts' "tech-tax", Massachusetts' adoption of economic nexus for sales tax, and enactment of the Massachusetts recreational Marijuana law. 

Sylvia is also a contributor to premier sales tax resource website,, where she blogs on eCommerce/Internet Sales Tax, Massachusetts Sales Tax, and U.S. Sales Tax for Foreign Sellers.  

She holds a Bachelor in Business Administration (BBA)  - Accounting from the University of Texas at El Paso, and a Masters in Professional Accounting (MPA) - Taxation Specialization, from the Red McCombs School of Business at the University of Texas at Austin.  Sylvia is a Certified Public Accountant (CPA).

Sylvia has been happily married for 25+ years, is the mother of a 21 year-old son and 16 year old twins, is a passionate foodie and cook, is fluent in Spanish and proficient in French. 

You can connect with Sylvia in the following ways:



Twitter:  @SylviaDionCPA,  


Interested in learning more about my services? 
Visit the Services webpage or Contact me

Interested in viewing my complete list of presentations, publications, blog articles, etc.?  View my Publications section at my LinkedIn Profile

Interested in having me present to your organization? Contact me.

News and Article Links

Sylvia Dion interviewed in article, "Sylvia Dion CPA Asks - Where Are the Women?"
by Peter J. Reilly  Article Link

Sylvia Dion makes FORBES - the TaxGirl's  "100 Must-Follow Tax Twitter Accounts"  for 5th Consecutive Year (2015-2019)

Select Published Tax Articles (Available for viewing/download by clicking on article icon )​

"US Supreme Court Overturns Physical Presence Standard," published in Leading Internet Case Law, August 2018

"MFA v RTPA: Will Changes in the House and An Expiring ITFA Help or Further Stall Federal Report Seller Bills," published in Bloomberg BNA Weekly State Tax Report

"From Click-Through to Marketplace to Economic Nexus: How Far Will States Push the Nexus Envelope on Remote Sellers?," published in Bloomberg BNA Weekly State Tax Report 

"Alibaba Differs From U.S. - Based Remote Sales Behemoths, But the Competitors Could Face Similar Sales Issues", published in Bloomberg BNA Weekly State Tax Report.

"U.S. Supreme Court May Rule on the 'Click-Through' Nexus," published in E-Commerce Law & Policy

"The Massachusetts 'Tech-Tax' Fiasco: It's History, Impact and Valuable Lessons Learned." published in the Institute for Professionals in Taxation (IPT) Tax Report

Sylvia Dion quoted in "It's Retailer vs. Retailer in Internet Sales Tax Push", Bloomberg BusinessWeek