HTML and PDF: the UK public sector position

What disproportionate burden means

The Public Sector Bodies (Websites and Mobile Applications) (No. 2) Accessibility Regulations 2018 require UK public sector organisations to make their websites and mobile applications accessible. Where making specific content fully accessible would impose a disproportionate burden on the organisation, a qualified exception applies. That exception is not automatic. The organisation must assess whether it applies, document the reasons, publish that position in its accessibility statement, and keep the assessment under review. The exception does not remove the obligation to provide information in an accessible format when a user requests it.

The Regulations do not define a precise financial threshold for disproportionate burden. The assessment requires organisations to weigh the costs involved against the resources available and the benefit to users of making the content accessible. A realistic, evidenced account of what the work actually costs is therefore central to any defensible burden position.

The scale of the task

Published accessibility statements and disproportionate burden assessments from UK local authorities provide a consistent picture of the PDF estates involved. A unitary authority reviewing its estate found over 5,800 PDFs, with 77% viewed 50 times or less and 49% viewed fewer than 5 times. A metropolitan council disclosed 1,440 downloadable files on its main corporate site, with 67% viewed fewer than 100 times in the past year. A district council found that 78% of its PDFs had not been viewed in the last 30 days. A Scottish council area reported that only 363 of its published documents had been viewed or downloaded from the corporate site over a 13-month period.

Evidence-based modelling using these published disclosures produces a working estimate of approximately 1,000 PDFs on a typical UK council corporate website, excluding committee management platforms such as Modern.Gov, which generate separate and constantly changing document volumes. That 1,000-PDF figure is a conservative starting point for any cost assessment.

The cost of manual remediation

Manual PDF remediation involves a specialist rebuilding the structure of a document so that it can be read correctly by assistive technologies. Industry data from specialist PDF accessibility vendors PDFix, Title2.info, and Equidox puts the average manual remediation time at 23 minutes per page. At a UK specialist rate of £40 per hour, that is £15.33 per page.

Applying a 10-page average per document, the cost of manually remediating a single PDF is approximately £153. Across an estate of 1,000 PDFs, the remediation cost alone is approximately £153,000.

That figure covers one activity only: the skilled technical work of making an existing PDF accessible. It does not include the time and cost of discovering what PDFs exist on the estate, locating all versions of each document across all pages and subdomains, managing updates when source documents change, republishing corrected versions, and maintaining the accessible versions over time as content is revised. These activities add material cost that varies by organisation and cannot be calculated precisely from available data. Organisations assessing their own burden position should estimate these separately based on their specific team structures, publication workflows, and update frequencies.

PDFs that cannot be remediated regardless of cost

A further dimension of the burden is the portion of an organisation's PDF estate where manual remediation is not possible at all, irrespective of resource. This includes:

• Scanned documents that exist as image files with no underlying text layer. These cannot be made accessible without first converting them using optical character recognition software, a process that introduces its own accuracy limitations and additional specialist time.
• Third-party documents that the organisation is required to publish but did not create and does not control. Published UK local authority accessibility statements confirm this is a material category.
• Signed, certified, or legally bound documents where the original file must remain unaltered to preserve its integrity as a record.
• Archived and legacy documents published before 23 September 2018, which under the Regulations may fall outside scope unless they are needed for active administrative processes.

The presence of these categories means that even a fully resourced manual remediation programme cannot achieve complete coverage of a public sector PDF estate. Any burden assessment that rests on the premise that full manual remediation is theoretically achievable does not reflect the actual position.

Why this constitutes a disproportionate burden

For a typical UK local authority, the combined weight of the cost, scale, ongoing management requirement, and structural impossibility of complete manual remediation represents a burden that is disproportionate to the resources available and, in many cases, disproportionate to the benefit delivered. Published council assessments reflect this consistently, with authorities citing limited staffing, competing priorities, the volume of third-party content, and the continuous rate at which new documents are published as factors that make comprehensive manual remediation impractical.

A disproportionate burden position documented on these grounds, with the supporting evidence referenced, is a defensible and appropriate position under the Regulations. It does not remove the obligation to improve access. It requires the organisation to describe what it is doing instead, and to maintain a route through which users can request content in an accessible format.

What a proportionate response looks like

Automation addresses the core of the burden directly. aicm discovers PDFs linked from an organisation's public-facing website and converts them into accessible web pages, delivered as HTML. The original PDF is not modified. The conversion runs continuously, covering new documents as they are published without manual intervention.

The accessible HTML output delivers 85%+ accessibility improvement out of the box, achievable across 93% of consumed government documents. The remaining variance is attributable to formatting complexity, not content. For the documents people actually use, the content is delivered accessibly and immediately.

The cost of automated conversion is a fraction of the manual equivalent. An organisation does not pay to process documents that no one is accessing. Conversion costs arise only when accessible content is served to a visitor. For an estate where the majority of PDFs receive very low or zero usage, this is a material difference from any model that charges for the full inventory upfront.

Automation also extends beyond the current regulatory minimum. The Regulations create a qualified exception for archived documents published before 23 September 2018 that are not needed for active administrative processes. Under a manual programme, those documents typically remain inaccessible because the cost of processing them cannot be justified. Automation makes it practical to extend coverage to archived material on request, increasing inclusion without requiring additional resource allocation or disruption to the organisation's existing workflows.