Accessibility cost analysis, Part 2: The rule of 100 for remediation cost

Accessibility cost does not grow linearly with delay. A defect that is inexpensive during design becomes materially more expensive when discovered after release under legal pressure.

The Rule-of-100 Heuristic

Product teams can use a straightforward planning heuristic:

  • 1x cost when fixed at design/system level
  • 10x cost when fixed during implementation/QA
  • 100x cost when fixed reactively in production under legal or regulatory timeline pressure

This is not a statutory rule; it is a risk-modeling tool that helps allocate budgets earlier where fixes are cheaper and less disruptive.

Why Late Fixes Spike Cost

Late remediation usually compounds four cost categories at once:

  • emergency engineering and QA cycles
  • legal response and stakeholder management
  • roadmap displacement of revenue features
  • repeated regressions if systemic controls are missing

That is why a recurring accessibility operating model is usually cheaper than intermittent clean-up projects.

A More Defensible Planning Approach

  • Define criteria up front (WCAG 2.2 AA mapped to your component system).
  • Gate releases with automated checks for recurring issue classes.
  • Reserve manual testing for high-impact flows and custom interactions.
  • Keep issue-level evidence so remediation can be demonstrated quickly.

Claim-level Citation Notes