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Owner – Sherri D. Gastelum

Sherri Gastelum is the owner of Platinum Tax Defenders LLC and has been a Senior Business professional with 20+ years of experience in new business generation, corporate business including marketing, sales, relationship management and operations. Specialize in working in the accounting, tax and business consultancy field. Sherri has expertise working with clients and prospects to provide the best solution possible. Previously worked for PricewaterhouseCoopers, Deloitte, RSM McGladrey and others before starting her own tax resolution firm. Earned a BBA in Business from the University of Louisiana in Monroe, Louisiana. Has most recently been in charge of running the day to day operations of Platinum Tax Defenders LLC. Responsibilities include client acquisition, client service, and financial operations of the firm.

Platinum Tax Defenders was founded by Sherri Gastelum because there were so many firms that were taking people’s money but not providing the services. Sherri envisions Platinum Tax Defenders as the shining example of what a tax resolution firm should be.


Worldwide Who’s Who
Better Business Bureau
National Association of Professional Women
Valley Industry and Commerce Association
PWC Alumni Group
International Women’s Leadership Association
National Association of Women Business Owners
Association of Corporate Growth
Financial Executive Institute
Deloitte Alumni Group


Lifetime member of Worldwide Who's Who (WWW)
Top Female Executive in honor of outstanding professional excellence and dedication by WWW
Recognized as the 2013 Entrepreneur of the Year representing the Tax Industry by WWW
Woman of Outstanding Leadership recognized by the International Woman’s Leadership Association
"A" rating with the Better Business Bureau
Recognized as the Top Tax Firm in the Best of Magazines in Southern California Area

Director of Resolution – Amy Nowak

Amy Nowak is a tax attorney and the Director of Resolution at Platinum Tax Defenders. She has over 13 years experience dealing with an array of tax situations and clients, including obtaining offer in compromises, currently not collectible statuses, and setting up payment plans for individuals and businesses with the IRS and various state entities.

Amy received her Juris Doctorate from Loyola University New Orleans College of Law and her LL.M. in Taxation from Boston University School of Law. Since graduation, Amy has spent her professional career specializing in tax resolution and business law.

Amy is a member of the Texas State Bar and the United States Tax Court.

Attorney – Gloria Chon, Esq.
Bio coming soon...

EA and Ex IRS Agent – Maurice Rossaler

Maurice Rosaler is an Enrolled Agent with over 27 years' experience in the tax resolution industry with over 18 years working at the Internal Revenue Service as a Senior Revenue Officer, Group Manager and Section Chief. He has extensive knowledge of the collections process, tax code and regulations necessary to investigate and resolve complex tax matters. After retiring with the IRS, Maurice spent the last 9 years working on the other side of the fence defending tax payers in resolving all matters of tax resolution.
Professional Activities

    Member of the National Association of Enrolled Agents
    Associate, Greater Los Angeles Federal Leadership Board
    Los Angeles Electronic Federal Tax Payment System Coordinator
    On-Job Instructor and computer resource contact
    Member, I.R.S. Community Outreach Steering Committee
    Formally assigned to Entertainment Specialty Group and International/Offshore Divisions


  • Settle Back Taxes
  • Tax Resolution Services
  • Tax Resolution
  • Help With Back Taxes
  • Tax Attorney
  • Tax Relief
  • Tax Relief Services
  • Back Taxes
  • Back Tax Relief
  • Bank Levy Releases
  • Offer In Compromise
  • Payment Plan
  • Revenue Officer Assistance
  • Irs Audits
  • Irs Tax Liens
  • Amending Tax Returns
  • Tax Preparation For Businesses and Individuals
  • Bookkeeping Services

Service Area

  • Simi Valley
  • Thousand Oak
  • Moorpark
  • Calabasas
  • West Lake Village
  • Pasadena
  • Glendale
  • Beverly Hills
  • Surrounding Areas.

Languages Spoken

  • English

Accepted Forms of Payment

  • Discover
  • American Express
  • Visa
  • MasterCard
  • Check
  • Debit
  • Cash

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