Older people are staying at home and not visiting their local town centre because of the lack of public toilets, a council report has found.
Many residents of Merthyr Tydfil were reluctant to use toilets where they felt obliged to buy something, it said.
The report warned of the risk of increased social isolation and to people's ability to live independently.
The Welsh Government has urged councils to work with firms and other partners to make more public toilets available.
Responses to a consultation showed a "significant gap" between the need and provision of toilet facilities available for public use, Merthyr Tydfil councillors heard on Wednesday.
The report said this had "a direct impact on whether people will venture away from home".
Cleanliness and the safety of some toilets were also raised as issues, as well as the lack of information on where the facilities can be found.
Councils in Wales are required to produce a toilet strategy, assessing local needs and working with businesses and other organisations to find solutions.
However, there is no legal duty for local authorities to provide public toilets themselves, according to the Local Democracy Reporting Service.
Merthyr Tydfil council has said information about locations, opening times, accessibility and other features will be made available online and via mobile apps.
Further consultation on the issue will be carried out in the new year.