In many cases, the word consumer connotes a legal definition that is different than customer.

For example, see the definition from Reg P: Consumer means an individual who obtains or has obtained a financial product or service from you that is to be used primarily for personal, family, or household purposes, or that individual's legal representative.

A customer may be an individual or a business.

Source: https://www.consumerfinance.gov/rules-policy/regulations/101...