The federal Civil Rights Act mandates that all persons shall be entitled to the full and equal enjoyment of the goods, services, facilities, and privileges, advantages, and accommodations of any place of public accommodation without discrimination or segregation on the ground of race, color, religion, or national origin.
A business can refuse service as long as their policies aren’t purposely discriminating against a person’s race, religion, sex, or national origin, which owners of cashless institutions would argue their policies aren’t. A number of cities posit their laws as preventing discrimination against low-income people, but low-income people aren’t a protected group.