This is the question I get asked more a lot, and the honest answer is: it depends. Which I know is frustrating. But the reason it depends is actually worth understanding, because it’ll help you evaluate quotes and spot when you’re being undercharged for something that deserves more work.
What drives the cost
Scope. The biggest variable by far. A ten-page marketing site and a complex SaaS application with authenticated user flows, data tables, custom form controls, and a rich text editor are not the same problem. One of those I can audit thoroughly in a day or two. The other might need a week or more, and that’s before you factor in retesting after fixes.
What kind of audit you want. There’s a wide spectrum. At the light end: a sample audit of a handful of representative pages, giving you a broad picture of your barrier types.
At the thorough end: full coverage of every template, every interaction state, edge cases in custom components, testing across multiple assistive technologies. The former gives you a sense of where you stand. The latter is what you need before publishing a conformance statement or submitting to a procurement requirement.
Who’s doing it. A large agency will charge significantly more than an independent specialist. Whether that premium is justified depends on the agency. Some have excellent people. Some have junior staff running automated tools with a senior name on the report. Worth probing.
The deliverable. A well-structured report that a development team can actually work from takes time to write. A list of axe output takes almost none. If the quote is very cheap, ask what the report actually looks like.
What “reasonable” looks like
I’m going to give you rough ranges based on what I charge and what I see in the UK market, knowing these vary with location and complexity.
A sample audit of a small site (covering key templates and journeys, manual testing, screen reader spot-checks, written report with prioritised findings) tends to sit somewhere in the low-to-mid thousands of pounds. Enough to give you a clear sense of where the problems are.
A comprehensive audit of a mid-complexity web application (full template coverage, multiple interaction states, thorough screen reader testing on multiple platforms, a report genuinely usable as a remediation backlog) is more expensive. That’s week-or-more territory. Budget accordingly.
Ongoing embedded work (reviewing designs before build, checking PRs, training sessions) tends to work better priced by time (day rate or monthly retainer) than per-project.
When cheap is actually expensive
I’ve seen cheap audits cause real problems. A client comes to me after having paid for a low-cost audit somewhere else. The report is basically automated tool output, maybe seventy findings, no prioritisation, no explanation of user impact, no fix guidance. The development team doesn’t know where to start. Adding to the backlog and nothing happens.
A good audit is usable. It tells your team what to fix first, why it matters, and how to fix it. The cost of that clarity is worth more than the cost of a longer findings list that sits in a folder.
The question to ask any provider
Ask them how their day rate breaks down against hours spent. A quote of £2,000 for an audit sounds very different if it’s two days of senior specialist time versus one automated scan and a few hours of report writing. Most good practitioners are transparent about this. If someone is cagey, that’s information.
What you shouldn’t do
Don’t buy an overlay.
I know that’s not the question you asked, but overlays get pitched as a “cost-effective alternative to an audit” and they genuinely are not.
They create new accessibility problems while claiming to fix old ones. Multiple major lawsuits have happened against companies using them. The pricing looks attractive; the liability is real.
If you’re trying to figure out what an audit of your site would actually cost, get in touch via my contact form and I can give you a proper estimate once I understand the scope.