Charities said that exclusion was seen across a wide range of services and venues.
Wayne Crocker, director at Mencap Cymru, said people might have a choice of going to an alternative cafe if another in town decided to stop accepting cash.
However, were a town’s only theatre – or one based in a university – to go cash-free, then some more vulnerable people would no longer be able to visit.
Ron Delnevo, from the Payment Choice Alliance, said leisure centres, parking services, and catering on public transport were among the many services that may no longer accept cash.
“We have some heart-rending stories from families of people with disabilities, who feel that when they don’t have cash accepted, it is robbing them of their self-esteem,” he said.
“This was their money and they had the right to spend it, and they are being told their money is no good anymore. They take that as implying that they’re no good anymore.”
The BRC said all large retailers were committed to accepting cash in their stores.