The Business Case for Web Accessibility, Without the Inflated Numbers

Accessibility business cases have a credibility problem, and it is self-inflicted. They are routinely built on statistics that are outdated, misquoted, or traceable to nothing at all — a $6.9 trillion market from a decade-old magazine article, a "ten times cheaper to build it in than retrofit" multiplier that comes from generic software engineering literature rather than any accessibility research.

This matters because a CFO who checks one number and finds it unsupportable will discount the entire argument, including the parts that are solid. And the parts that are solid are strong enough on their own.

Here is the case, with each figure sourced and each weak claim flagged as weak.

How many people this affects

Globally, the World Health Organization estimated in 2023 that 1.3 billion people experience significant disability — 16% of the world's population, about 1 in 6. If you have seen "1 billion, 15%", that is the older figure from the 2011 World Report on Disability and it has been superseded.

In the United States, the CDC reports that over 70 million adults — more than 1 in 4 — have a disability, based on 2022 survey data. The breakdown by functional type is more useful for web work than the headline: cognition 13.9%, mobility 12.2%, independent living 7.7%, hearing 6.2%, vision 5.5%, self-care 3.6%. These overlap, so they do not sum to the total.

In the European Union, Eurostat reported that 23.9% of people aged 16 and over had an activity limitation in 2024 — 17.2% with some limitation and 6.7% with a severe limitation. The figure rises steeply with age, from 7.1% among 16 to 24-year-olds to 72.3% among those aged 85 and over.

On vision specifically, the WHO estimates that at least 2.2 billion people have a near or distance vision impairment, and that for at least 1 billion of them it could have been prevented or is yet to be addressed.

Two things follow from these numbers that are more useful than the numbers themselves.

First, cognitive disability is the largest single category in the US data, ahead of mobility and far ahead of vision. Accessibility discussions default to screen readers, but the largest group is served by things like clear language, consistent navigation, forgiving forms and not demanding that people memorise things — which is exactly what WCAG 2.2's new criteria on redundant entry, consistent help and accessible authentication address.

Second, prevalence rises sharply with age. If your customers include people over 65, the proportion with a relevant impairment is far higher than the population average. This is the argument that lands hardest with businesses whose customer base is not young.

The spending power argument, quoted correctly

The Return on Disability Group's *Global Economics of Disability 2024* is the standard source, and it is routinely misquoted. The headline figure of $18.3 trillion is a global market including friends and family, not the disposable income of disabled people.

The figures that are defensible as stated:

• US disposable income of people with disabilities: $1.3 trillion.
• Canada, EU, UK and US combined, people with disabilities: over $2.6 trillion in disposable income.
• ROD counts approximately 1.58 billion people globally with a disability, and estimates the market "directly touches an additional 2.9 billion individuals globally" through friends and family — which together is where its claim that disability touches 63% of the global population comes from.

Use the $1.3 trillion or $2.6 trillion figures and describe them accurately. They are large enough to make the point without needing the friends-and-family multiplier that invites a sceptical question you cannot answer.

On lost revenue specifically, the UK's Click-Away Pound survey estimated £17.1 billion in online sales lost to sites disabled shoppers abandoned. Cite it with its date — 2019 — and note that it is an independent survey rather than peer-reviewed research. It is directionally useful and it is seven years old.

The claim you should stop making

There is no credible published study establishing a cost multiplier for retrofitting accessibility versus building it in.

The "10x" and "100x" figures that appear in almost every accessibility deck trace back to general software defect-cost literature from the 1980s and a 2002 NIST report — not to accessibility research, and the underlying multiplier is itself disputed within software engineering. The Forrester study commissioned by Microsoft that is often cited alongside them is a qualitative piece about organisational benefits; we have not found a quantified retrofit-versus-build-in cost comparison in it, or in any other published source.

The honest version of this argument does not need a number: fixing a design system component once is obviously cheaper than fixing its output on four thousand pages, and anyone who has managed a codebase knows it. Say that. Do not attach a fabricated multiplier to it.

The arguments that survive scrutiny

Legal exposure is real and measurable. In the US, over 5,000 digital accessibility lawsuits were filed in 2025, with 2026 tracking higher, and 1,427 of them — about 45% of federal filings — targeted companies that had already been sued once. Most defendants are not large companies — in 2026 midyear data, 68% had revenue under $50 million. In the EU, the European Accessibility Act has applied since June 2025, and in June 2026 a French court ordered a major retailer to make its site fully accessible within six months under a daily penalty, holding that 71% conformity was not enough. This is not hypothetical risk any more.

Accessibility work is largely quality work. Semantic markup, keyboard operability, sensible heading structure, labelled forms, sufficient contrast and clear error messages are not disability features. They are the things that make a site work reliably on a phone in sunlight, with a slow connection, for a user in a hurry. Captions are used heavily by people with no hearing impairment. Good heading structure helps search engines parse your content. There is no separate accessibility website; there is a well-built one and a poorly-built one.

Procurement increasingly demands it. If you sell software to governments — US federal under Section 508, EU public sector, Canadian federal entities under the new regulations that phase in from December 2027 — you will be asked for an Accessibility Conformance Report. Not having one removes you from the bid. This is the argument that moves B2B companies fastest, because it is a revenue gate rather than a risk.

Your competitors' failures are your opportunity. WebAIM's February 2026 analysis found detectable WCAG failures on 95.9% of a million home pages, averaging 56.1 errors each — and the trend actually worsened from 94.8% the previous year. In a market where nearly everyone is failing, being usable is a differentiator available to anyone willing to do fairly ordinary work.

What it actually costs

Be realistic here too, because inflated benefit claims paired with hidden costs is how accessibility programmes lose credibility internally.

For a typical small or mid-sized site, the work divides into three buckets. Automated scanning and fixing the mechanical failures — contrast, alt text, labels, empty controls — is the bulk of the error count and the cheapest to clear. Manual testing and remediation of critical journeys is the expensive part, because it needs skilled human time. Ongoing monitoring is small but must be continuous, because sites regress: the UK's public sector programme retested 47 sites it had already assessed and found only 3 with no issues.

The sequencing that keeps costs sane is to fix the design system and shared templates first — components, colours, form patterns, focus styles — because those fixes propagate everywhere, then work outward to individual content.

The argument that does not need a spreadsheet

All of the above is true, and none of it is the actual reason.

A person who cannot complete your checkout because your form fields have no labels is not a market segment or a compliance risk. They are someone who wanted to buy something from you and could not, for a reason that took your developer twenty minutes to create and would take twenty minutes to fix.

Most organisations that build serious accessibility programmes did not do it because of a spreadsheet. They did it because someone watched a real person fail to use their product. If you can arrange that — one session, one screen reader user, one checkout — you will not need the statistics.

*Prevalence figures are from the WHO disability fact sheet (2023), the WHO blindness and vision impairment fact sheet (2026), CDC data based on the 2022 BRFSS, and Eurostat EU-SILC data for 2024. Market figures are from the Return on Disability Group's Global Economics of Disability 2024 and the Click-Away Pound survey 2019. Litigation figures are from UsableNet's 2025 year-end and 2026 midyear reports. Failure rates are from the WebAIM Million 2026 report (analysis run February 2026, published March 2026), which notes that automated tools cannot detect all conformance failures.*