Advanced Personnel, Inc. (formerly CSI Staff, Inc.)
Affymetrix, Inc.
Agilent Technologies, Inc
Airgas North Central
American Bottling Company (now known as Dr Pepper Snapple Group)
American Courier Service, Inc. 
Applied Biosystems
A-Pro Staffing LLC
Avenue Crowne Plaza Hotel

Banner Personnel Service, Inc.
Barnes & Noble (The Univ of Chicago Bookstore)
Beckman Coulter, Inc (Capital Equipment)
Beckman Coulter, Inc (Maintenance)
Becton Dickinson Discovery Labware
Bio-Rad Laboratories
BOC Gases (now known as Airgas North Central)
BostonCoach Connection Service

Carl Zeiss Microscopy, LLC
Cedars Mediterranean Kitchen
Cheesecakes by JR
Chicago Diner
Chicago Gourmet Bakery
Citibank, F.S.B.
Clinton's Limousine Services
Cleaning Technologies Group
Club Quarters, Boston
Club Quarters, Gracechurch, London
Club Quarters, Houston
Club Quarters, Lincoln's Inn Fields, London
Club Quarters, Midtown
Club Quarters, Philadelphia
Club Quarters, Rockefeller Center
Club Quarters, San Francisco
Club Quarters, St.Paul's, London
Club Quarters, Trafalgar Square
Club Quarters, Wacker Drive
Club Quarters, Wall Street
Club Quarters, Washington
Club Quarters, World Trade Center
Coca Cola Enterprises
Comfort Suites Chicago
Connect by Hertz
Continental Carbonic Products, Inc.
Corning Incorporated Corporate Concepts
CSI Staff, Inc.(now known as Advanced Personnel, Inc.)

Dearborn Wholesale Grocers, Inc.
Dell Marketing L.P.
Details
Doctors Laundry Services, Inc.
Dr. Pepper Snapple Group
Edwardo's Natural Pizza
Embassy Coffee (New Preferred Coffee Supplier)
Emerald Plant Services Inc.
Enterprise Rent-A-Car
Equal Exchange, Inc.

Federal Express Corporation
Federal Surplus Property Program
Fisher Scientific
Food Evolution
Four Seasons Hotel Chicago

Getinge USA, Inc.
GO Airport Express
Grabel Companies

Hallett Movers
Henricksen & Co. Inc
Hilton Chicago
Hinckley Springs
Hogan & Sons Moving & Storage LTD, Inc.
Homewood Suites by Hilton
HireRight
Holiday Inn Chicago Midway Airport Hotel
Hotel Program Univ of Chicago 2012 [PDF]
Hyatt Regency McCormick Place Chicago

Ice Mountain
I-GO
Illumina Inc
Inn of Chicago
Integrated DNA Technologies (IDT)
InterContinental Chicago
Interior Investments, LLC
Invitrogen Corporation (now Life Technologies)

Jackson Laboratory
J & L Dairy, Inc
Joe & Ross Ice Cream, Inc.
Justice Perry Transportation and Limousine Service

La Petite Pastry Shop, Inc.
Laser Cat
Lechner and Sons Uniform Rental
Life Technologies
Lincolns Tasty Sandwiches
Livery Managements Services, Inc. (now known as SCI Processing, Inc) Lufthansa German Airlines

Mallory Alexander International Logistics (formally Quast & Co. Inc.)
Maravillas Restaurant
Medici on 57th
M & M The Special Events Company
Murnane Paper Company

Naked Juice
National Car Rental
New England Biolabs, Inc.
Nile Restaurant
Novamed Incorporated

Omni Chicago Hotel

Peninsula Chicago
Perkin Elmer Life & Analytical Science
Pizza Capri
Power Distributing, LLC

Qiagen, Inc.
Quast & Co. Inc. (now known as Mallory Alexander International Logistics)

Radisson Blu Aqua Hotel Chicago
Ramada Hotel Chicago Hyde Park
Research Productions International
Residence Inn Chicago Downtown Mag Mile
Residence Inn Chicago Midway Airport Hotel
Right Staffing Services (now known as Stivers Temporary Personnel)
Ritz-Carlton Chicago
Roche Diagnostics Corp

SmartCars, Inc.
Seoul Corea, Inc.
Secure Eco Shred
Service Dairy, Inc.
Shaker Advertising Agency
Sigma-Aldrich, Inc.
Silversmith Hotel & Suites
Skandia Foods/dba DPI
Southwest Beer Distributors
Stable Foods, Inc.
Staples Advantage
Starwood Preferred Business
Stivers Temporary Personnel
Sun Microsystems
Super Steak Sub
Swissotel Chicago

Tower Travel Management
Trump International Hotel & Towers

United Airlines
United Van Lines
Universal VAT Services
University Bookstore
University Market
US Media, Inc.
US Foodservice, Inc

VWR International
W Nuhsbaum, Inc.
ZipCar