Millions of pounds a month are lost by UK shops and businesses because they are not accessible to people with disabilities, according to an awareness campaign.
Purple Tuesday, which says a "mindset change" is needed, is urging retailers to consider new ways of improving inclusion such as adapting sensory experiences for neurodivergent people.
Some 16 million people in the UK have a disability, and 90 per cent of disabled people found their shopping experience was affected by a lack of accessibility, according to the Business Disability Forum.
Mike Adams, the founder of Purple Tuesday, says retailers and others who offer services need to make changes to the way they operate to attract disabled shoppers.
Adams told BBC London, "In terms of the disability population, wheelchair users comprise 8 per cent.
"So we need to think about how businesses can support the other 92 per cent - people with mental health, neurodiversity, long-term health conditions - where some of the accessibility changes that are required aren't physical ramps and lifts but are more mindset changes that actually cost very little or nothing."
Purple Tuesday, which is in its eighth year, said research from the University of Bristol and the Money Advice Trust revealed the combined spending power of disabled households in the UK is £446bn a year.
Government research published in July on the accessibility of private-sector products and services for disabled people in the UK found that 88% of people with disabilities had to use workaround solutions, external or compromises when accessing retail businesses.
The Business Disability Forum said in its response to the research that businesses "are putting up barriers which prevent more disabled people spending more money with them".
The advocacy group added: "Adjustments and accessibility here are really about removing a difficulty which gets in the way of someone spending money with a business.
"If the legal and moral case that every human being is valuable and of equal worth in society doesn't land with businesses, the profit case certainly should."