Accessibility statement

Commitment and standard

The site aims to meet the Web Content Accessibility Guidelines version 2.1 at level AA, which is the standard referenced by European accessibility requirements. That aim is treated as a working target rather than a completed achievement: the statement below describes measures taken and limitations known, and it is revised as either changes.

This is a self-assessment. No external audit or certification has been carried out, and the statement says so rather than implying formal verification.

Measures taken

Structure and navigation

Pages follow a consistent order so that a reader using a screen reader can predict where things are: notice strip, header with navigation, main content, then footer. Long guides carry a section index of ordinary anchor links, so navigation works without scripting and each section keeps a stable identifier that remains valid when the text is revised.

Link text is written to make sense on its own, since assistive technology can present links out of context. Phrases like "click here" are avoided, and links that lead to the same place use the same wording throughout the site.

Colour, contrast and type

Colour is never the only way information is conveyed: categories in tables and charts carry labels or text as well as shading, and validation messages are words rather than a red border alone. Contrast ratios for body text meet the AA threshold, and larger display text is checked separately against its own threshold.

Type sizes are set in relative units so that a reader's own browser setting is respected. No text is embedded in an image, so everything can be resized, selected, translated or read aloud.

Interactive elements

The entry notice is a dialog with an accessible name, keyboard focus moved into it on opening, focus kept within it while it is open, and focus returned to a sensible place when it closes. The cookie banner is reachable by keyboard and can be reopened from a control in the footer.

The calculator uses native form controls with labels, does not rely on browser validation messages alone, and announces its result in a politely updated live region so that a screen reader reports the outcome without interrupting.

Small screens, zoom and reflow

The layout is built from a single flexible column arrangement rather than a fixed grid, so it reduces to one column on a narrow screen and at high magnification without a second, separately maintained mobile version that could fall behind the main one. Text is set in relative units, which means a reader who has increased the default font size in the browser gets larger text here without changing anything, and no line of text is clipped or overlapped when that happens.

At two hundred per cent zoom the pages reflow rather than requiring horizontal scrolling, with one exception noted in the table below: wide comparison tables scroll sideways inside their own container so that the surrounding text does not. Sticky elements are limited to the header and the section index of long guides, and both release their position on narrow screens, because a bar pinned to a short viewport takes reading space from the person who has least of it.

How tables and figures are built

Every table carries a caption naming what it contains, a header row marked as such, and a first cell in each row marked as that row's header, so that assistive technology can announce which column and which row a value belongs to instead of reading a stream of unlabelled cells. Column headers are short and literal for the same reason.

Tables are also never the only place a finding appears. Where a row carries the point of a section, the point is stated in the surrounding prose as well, which serves readers navigating by screen reader, readers on a phone and readers who simply do not read tables. The diagram on the home page follows the same rule: its text alternative states what it shows, and the values it illustrates appear in the text beside it.

How the site is checked

Checking is done as four separate passes rather than by running one automated report, because the common failures are structural. A keyboard-only pass reaches every control in order and confirms that focus is always visible and never trapped outside the entry notice. A magnification pass at two hundred per cent looks for clipped text and lost controls. A contrast pass measures body, secondary and display text against the AA thresholds. A structural pass reads the heading order and the link text of a page in isolation, as assistive technology presents them.

These are self-checks by the publisher, carried out when a page changes and at each annual review. No external audit, certification or accessibility conformance assessment has been carried out, and this statement claims none.

Known limitations

Area	Limitation	Position
Wide tables	Horizontal scrolling on narrow screens	Captions and row headers provided; restructuring under review
Dense data tables	Demanding to navigate by screen reader	Findings also stated in the surrounding text
Diagrams	Text alternatives are necessarily brief	Key values repeated in adjacent prose
Without JavaScript	Notice and banner do not appear; calculator shows no result	All reading content remains fully available
External documents	Sources cited may be inaccessible PDFs	Outside this site's control; described in the text

Reporting an obstacle

If something on this site cannot be used with your technology, a report is genuinely useful. Please send the page address, what you were trying to do, the technology and version you are using, and what happened. Reports are answered within five working days.

Where a fix is not immediately possible, the reply will say so and, where practical, an alternative way to reach the information will be offered. Where a report reveals a limitation not listed above, the table on this page is updated.

Review

This statement is reviewed at least annually, and whenever a change to the site's structure, layout or interactive components could affect accessibility. The review date is shown at the foot of the page.

The statement describes practice on this website only. It is general information rather than advice on any accessibility obligation that may apply to you.