Did you know there are at least **1,005** official SIC codes in the U.S. system, the four-digit industries in the 1987 manual that governments still treat as the standard.
Some say as many as **10,000+**, which is the commercial layer. Private data firms took those 1,005 official codes and split them into 6-digit (and sometimes 8-digit) marketing codes so they could target narrower slices of a business.
Then in payments we have another system that actually sets your merchant fees: MCC codes. Those sit between about **880 and 930**, depending on the source. Visa lists 887, Mastercard 879, Amex 890. Broader vendor catalogs push it toward 930 once they fold in every airline, hotel, and rental-brand code.