Some of QSI's past and present clients are listed below:
State Regulatory Agencies: Colorado Public Utilities Commission, Connecticut Department of Public Utility Control, District of Columbia Public Service Commission, Hawaii Public Utilities Commission, Maine Public Utilities Commission, Maryland Public Service Commission, Nebraska Public Service Commission, New Mexico Public Regulatory Commission, New York Public Service Commission, Oregon Public Utilities Commission, South Dakota Public Utility Commission, and Wyoming Public Service Commission.
Federal Agencies: U.S. General Services Administration, U.S. Department of Defense and Federal Executive Agencies.
Consumer Advocates & Other State Agencies: Colorado Office of Consumer Counsel, Connecticut Attorney General, Idaho State Tax Commission, Illinois Department of Revenue, Maryland Office of the People’s Counsel, Massachusetts Department of Revenue, New Mexico Attorney General, Oregon Department of Revenue, Texas Office of Public Utility Counsel, and Wyoming State Legislature.
Wireline Telecommunications carriers: Comcast, Level 3 Communications, Charter Communications, tw telecom, One Communications (n/k/a Earthlink Business), PAETEC Communications (n/k/a Windstream), XO Communications, TDS Metrocom, ATX Communications, Integra Telecom, Bermuda Telephone Company Limited, ClearTel Communications, Conversent Communications, Iowa Telecom, Coon Creek Telephone Company, Midcontinent Communications, Core Communications, Covad Communications, Lucre, NuVox Communications (n/k/a Windstream), Sage Telecom, Socket Telecom, WorldNet Telecommunications.
Wireless Telecommunications carriers: Bell Canada Mobility, Rogers Communications, T-Mobile, Mobi PCS, Shaw Communications, Quebecor Mediatron, Centennial Wireless (n/k/a AT&T).
Energy Companies: BC Hydro, Comm. Marathon Oil, El Paso Energy, Toronto Hydro, Washington Gas & Light Co., Wyoming Indusrial Energy Consumers
Industry Member Associations: CompSouth, Missouri Pay Telephone Association, Payphone Association of Ohio, Wisconsin Pay Telephone Association, Association for Local Telecommunications Services, and Midwest Association of Competitive Carriers.
Law Firms: Davis Wright Tremaine, LLP, Kelley Drye and Warren LLP; Sidley Austin Brown & Wood LLP; Bingham McCutchen LLP; Davis Polk, Londrigan, Potter & Randle P.C., Davis Polk, and Doffermyre Shields Canfield & Knowles.