What is ISO 18245?
ISO 18245 is the international standard titled "Retail financial services: Merchant category codes". It defines code values used to group merchants by type of business, trade or service. Its second edition was published in February 2023. Card schemes publish their own MCC lists based on the same four-digit structure.
In detail
ISO 18245 is the standard behind merchant category codes. Its full title is "Retail financial services: Merchant category codes", and the current version is the second edition, published in February 2023.
What it defines
The standard defines code values that group merchants by type of business, trade or service. The codes have four digits. The standard provides the classification. It does not mandate how each scheme or acquirer must use it.
How it relates to scheme lists
Visa and Mastercard publish their own lists. Visa’s is in its Merchant Data Standards Manual. Mastercard’s is in its Quick Reference Booklet, which runs from 0742 to 9406 and reserves ranges for airlines, car rental and lodging. The lists are close to each other and to the ISO standard, with differences in some categories. An acquirer must follow each scheme’s list for that scheme’s transactions.
For operators, three points matter:
- Onboarding: each merchant needs a valid code for each scheme.
- Messages: the code is carried in a four-digit field of ISO 8583, the message standard.
- Maintenance: lists change, and new codes appear.
See MID and TID for how the code attaches to an account, and the merchant category code episode for how it is used. Codes are set during payment stack activation.