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About US


Mark "Coach" Mirsky leads the Taxation and Management Advisory Services teams at ROI Business Services, LLC. Mark focuses on partnership, S corporation, and multi-state taxation as well as counseling startups, mergers and acquisition of businesses, and interational taxation. While Mark works with manufacturing/distribution, service firms, and related industries, he also represents a variety of clients including retail, healthcare, technology, virtual currency and web-based businesses, real estate, construction, and individuals.

Mark's background includes working in the international tax group at one of the largest accounting firms in the world as well as two middle market firms located in the Chicago suburbs, focusing on closely held businesses serving as a firm wide resource for partnership taxation, international taxation, and multi-state taxation.

Mark is an Illinois licensed CPA. He also has a Masters in Taxation from University of Illinois, Urbana-Champaign. He is a member of the AICPA and ILCPAS. Mark was selected to teach fellow CPAs at the AICPA National Tax Education Program. Mark is currently an instructor with TaxSpeaker teaching CPAs and EAs around the country and has taught in the past for the AICPA (9 years), Western CPE, Vern Hoven Tax Seminars teaching partnership, S corporation, C Corporation, and individual taxation, as well as tax law updates. He was a panelist for the first local Public Forum for the National Taxpayer Advocate office.

Mark is a community leader and served as Chairman of the Board for the Bartlett Chamber of Commerce and sat on the committee to create a Transit Oriented Development Plan for the Village of Bartlett. He is also a soccer enthusiast having been to one UEFA Euro Cup and three FIFA World Cups including Russia. Currently Mark is the Assistant Women's Soccer Coach at Aurora University. Previously, Mark was an Assistant Varsity Boys and Girls Soccer Coach for Bartlett High School.


Kathy Naffier

Kathy Naffier is a Director at ROI Business Services, LLC. Kathy joined ROI in 2007 and heads our individual and closely held business practice. She has been providing clients with tax, consulting, and accounting services for over twenty years. While running her own accounting firm for fourteen of those years, Kathy was well known for her speaking engagements aimed at educating small businesses and individuals in tax planning and record-keeping. Kathy has also served on the boards of several not-for-profit organizations. Due to Kathy's extensive background, ROI is able to provide our small business clients comprehensive accounting services, tax planning and consulting support.

Kathy has a BS in Accounting from Elmhurst College and is an Enrolled Agent, (EA), enrolled to represent taxpayers before the Internal Revenue Service. She is a member of the AICPA, and has served on the Board of Directors for the ILSEA - Fox Valley Chapter. Kathy is also a member of the National Association of Enrolled Agents & the Illinois Society of Enrolled Agents.


Michael Sutcliffe is a founding member of ROI Business Services, LLC who specializes in providing CFO controllership and accounting services for small to mid-size manufacturing and service businesses optimizing cash flow and overall profitability. Prior to starting ROI, Mike was an owner/CFO in a successful start-up health care manufacturing company concluding with the sale of the business. His 25 years of financial experience includes raising capital, implementing accounting systems, developing comprehensive financial reports, cash flow forecasting, budgeting, product costing, long term strategic planning, implementing company risk management and benefit plans, and other functions as necessary in a start-up situation.

Mike is a member of the American Institute of Certified Public Accountants and the Illinois CPA Society.


Kathy Naffier

Jason Luksis has over 10 years of experience in tax compliance and accounting.  His tax background has focused on compliance and tax planning for pass-through entities, individuals, trusts, and international tax concerns for individuals.  His clients have included privately held businesses in manufacturing, online retail, medical practices and other service fields, as well as real estate and private equity funds.  He also has direct experience with QuickBooks, period accounting, compiled financial statements, and payroll, areas he learned working at smaller market firms not necessarily shared by his contemporaries in pure tax compliance departments.  He views the span of his experiences at various size accounting firms as a benefit that helps him interpret and service the tax needs for a wide range of clients.  

Jason holds a Bachelor of Science from the University of Illinois at Urbana-Champaign.  As an undergrad student, he was selected for a student committee that provided feedback on a new course being developed for the College of Business, and he was later among the first cohort of undergrads to serve as teaching assistants.  


Priyanka Patel

Priyanka Patel is a Senior Accountant at ROI Business Services, LLC. Priya has over seven years extensive experience in taxation and accounting. She is involved in preparing financial statements, bookkeeping review, QuickBooks training, payroll and sales tax preparation, and business and individual tax returns.

Priya has a B.S. in Accounting and is an Enrolled Agent (EA), enrolled to represent taxpayers before the Internal Revenue Service. She is certified as a QuickBooks Online ProAdvisor. She is a member of the National Association of Enrolled Agents and the Illinois Society of Enrolled Agents, and is active in the Fox Valley Chapter of the ILSEA.


Kelly Dirks

Kelly Dirks is a Staff Accountant at ROI Business Services, LLC. She began working in QuickBooks at her father's business as a teenager. After earning an Associates degree in Paralegal Studies, Kelly worked as a Paralegal for 15 years. With a desire to work on the financial side of business again, she earned a second Associates degree in Accounting. Kelly now has over 25 years of experience with QuickBooks.

Kelly has extensive bookkeeping experience for service-based companies including lawfirms, ABA service providers, private schools and churches. She has experience with sales tax, payroll and preparing financial statements. Kelly is a certified ProAdvisor for QuickBooks Desktop and QuickBooks Online Advanced.


Sharon Mirsky leads the administrative team at ROI Business Services, LLC as the office manager. Sharon's background is in the education and recreation fields. She has a BS in Education and a MS in Leisure Studies/Sport Management from the University of Illinois. Sharon switched gears and joined ROI in 2008 to relieve Mark of some of the administrative duties. She is currently responsible for building maintenance, general client communication, files and records keeping, accounts receivable, human resources, and assisting the tax and accounting staff as needed. Contact Sharon if you need to schedule appointments, exchange documents, make payments, or to ask general questions. 


Krissy DeMarco

Kristina DeMarco has been an Office Assistant with ROI since January 2020. Her background has primarily been in the retail industry providing leadership and assistance to store managers resulting in smooth operation and organization at a store level. Within that time, she also obtained skills in office administration as an Assistance Fund Coordinator for almost two years. As an Office Assistant with ROI, she helps the Office Manager with the maintenance and organization of files and record keeping, electronic file exchange, the scheduling of appointments, payment processing, and some human resource management. She is also becoming more familiar with tax forms and processes in order to aid the tax and accounting team as needed. She is currently pursuing her Associates Degree in Arts.

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