A disability group wants it to be compulsory for retailers to have mobility parking.
CCS Disability Action called for a change in legislation allowing the mobility parking scheme to be extended to commercial premises.
Chief executive David Matthews said the organisation surveyed retailers and building owners for a consistent nationwide approach to policing mobility parking.
"The majority of retailers and building owners it has surveyed were unaware the present legislation only applies to public, not private areas such as retail grounds," he said.
Mobility parking permit holders can use mobility parking spaces, which are wider than standard parks and closer to venues. These spaces are marked with the disability symbol, and in many areas are painted blue.