Level AA is the baseline most accessibility laws actually adopt

What it is

Tender documents rarely say “please be somewhat accessible.” They say “must meet WCAG 2.1 AA,” or they name a harmonised standard that already wraps AA. The European Accessibility Act, EN 301 549, the revised US Section 508 for public bodies, China’s IT standard for internet content — the middle level keeps showing up as the enforceable default. AA is not a taste. It is the band most legislators have actually been willing to write into law.

A baseline is not a ceiling. Law picks it because a lower band would omit contrast and captions — already stably measurable — and a higher band would make whole classes of content unlawful.

Why it happens

What legislation can mandate is the layer that is measurable, litigable enough, and achievable for most content types. A is too thin: many jurisdictions will not call “it opens and it Tabs” publicly accessible. AAA is too thick: sign language, extreme contrast, site-wide reading level cannot be general policy without injuring whole publishing classes. AA sits in between — repeatable measures (contrast ratio, keyboard traversal, presence of captions) without netting photography, live work, and specialised text in one sweep.

The second layer is the citation chain. Statutes often do not copy the success-criteria list; they cite a harmonised standard or a procurement clause that already includes WCAG AA. “We tested AAA items from a later draft” does not automatically satisfy “the AA named in the tender”; scanning only A does not either. The baseline’s force comes from being named, not from being technically the most complete.

Studying it

Build a statute-to-protocol table, not a case-law story. For each target market, copy the standard and level named in the legal or procurement text, and set them beside the test protocol in use. GOV.UK and EN 301 549 statement templates show which level a public buyer expects to see. Lining up EAA, ADA Title II, and China’s internet-content standard is about scope and cited level — not about who punishes harder.

Independent variables: level named in the jurisdictional instrument, level actually covered by the test protocol. Dependent variables: whether named and tested levels are the same band; which named success criteria drop out if the team only tests A or only chases AAA.

This is document comparison, not a lab. Do not inflate “most laws write AA” into “AA is enough for every user” — that confuses a baseline with a sufficient condition.

Where it stops holding

Markets with no mandate, or with encouragement only, may have no AA line on paper; contract or platform policy can still demand the same band. Some sector standards (broadcast, educational publishing) add mandatory AAA items on top of AA; that is a sector add-on, not a rewrite of the middle level. The WCAG year used in testing still has to match the year the instrument cites — that is a version problem, not the meaning of the level. In some jurisdictions the private sector is not on this hook at all; that is scope of application, not AA-as-baseline failing.

Applying it

• Open the applicable statute or tender and copy the named standard+level into the first line of the test plan; aim the protocol at that band, not at the team’s favourite “latest” or “A first.”
• For public procurement, assemble evidence in the buyer’s statement template (which pages, which level, which date). An internal AAA wish-list does not substitute.
• Treat AA as the delivery gate, and list separately what you still plan above it, so the gate is not rewritten as the product goal.
• How to check: the report cover and the statute/tender use the same level string, character for character; pick three AA success criteria and see whether the report holds matching evidence. A mismatched string, or evidence only at A, means the baseline has not been aimed at.

Related

• Same group: J1.02.1 Conformance levels measure how far criteria are met, not which barriers matter more · J1.02.3 Level AAA cannot be treated as a site-wide requirement for every content type
• Nearby: J1.04 Legal requirements · J1.03 Ergonomics standards · J1.10 Scope of conformance claims
• Search terms: Level AA · EN 301 549 · legal baseline