Visa assigns every business an MCC (merchant category code), based on the industry of that business.  Sometimes only companies within a particular MCC code, or set of MCC codes, can qualify for a particular interchange rate.  One common grouping of MCCs is those that Visa defines as being Business to Business meaning that they sell primarily to other businesses rather than consumers.

MCCs defined as Business to Business:

• Horticultural Services (0780)
• Contractors – Special Trade, Not Elsewhere Classified (1799)
• Miscellaneous Publishing and Printing (2741)
• Typesetting, Plate Making, & Related Services (2791)
• Specialty Cleaning, Polishing, and Sanitation Preparations (2842)
• Delivery Services – Local (4214)
• Office and Commercial Furniture (5021)
• Construction Materials, Not Elsewhere Classified (5039)
• Office, Photographic, Photocopy, and Microfilm Equipment (5044)
• Commercial Equipment, Not Elsewhere Classified (5046)
• Medical, Dental Ophthalmic, Hospital Equipment and Supplies (5047)
• Metal Service Centers and Offices (5051)
• Electrical Parts and Equipment (5065)
• Plumbing and Heating Equipment and Supplies (5074)
• Industrial Supplies, Not Elsewhere Classified (5085)
• Durable Goods, Not Elsewhere Classified (5099)
• Piece Goods, Notions, and Other Dry Goods (5131)
• Men’s Women’s and Children’s Uniforms and Commercial Clothing (5137)
• Commercial Footwear (5139)
• Chemicals and Allied Products, Not Elsewhere Classified (5169)
• Books, Periodicals, and Newspapers (5192)
• Florists’ Supplies, Nursery Stock and Flowers (5193)
• Paints, Varnishes, and Supplies (5198)
• Non-durable Goods, Not Elsewhere Classified (5199)
• Insurance Sales, Underwriting, and Premiums (6300)
• Advertising Services (7311)
• Commercial Photography, Art and Graphics (7333)
• Cleaning and Maintenance, Janitorial Services (7349)
• Employment Agencies, Temporary Help Services (7361)
• Computer Programming, Integrated Systems Design and Data
  Processing Services (7372)
• Information Retrieval Services (7375)
• Computer Maintenance and Repair Services, Not Elsewhere
  Classified (7379)
• Management, Consulting, and Public Relations Services (7392)
• Business Services, Not Elsewhere Classified (7399)
• Motion Pictures and Video Tape Production and Distribution (7829)
• Testing Laboratories ( non-medical) (8734)
• Accounting, Auditing, and Bookkeeping Services (8931)
• Professional Services ( Not Elsewhere Defined) (8399)