Updated July 2026. Written by Tax Dispute Consultants, specialist ex-HMRC tax investigation team. Read time: 9 minutes.

An HMRC enquiry is stressful for anyone. For a taxpayer with a disability, whether a mental health condition, a chronic illness, a learning difficulty or a physical impairment, the standard process, tight deadlines, dense correspondence, formal interviews, can create a barrier that has nothing to do with the merits of the underlying tax position. HMRC's obligations do not stop at being polite about this. It has a specific, legal duty to make reasonable adjustments, and knowing how to invoke it properly changes how an enquiry is run.

The legal basis: section 20, Equality Act 2010

HMRC is a public authority exercising a public function, and as such is bound by the Equality Act 2010 in how it deals with taxpayers, not just as an employer. Section 20 of the Act imposes a duty to make reasonable adjustments where a provision, criterion or practice, or the absence of an auxiliary aid, puts a disabled person at a substantial disadvantage compared with someone who is not disabled. "Disability" under the Act is defined broadly: a physical or mental impairment that has a substantial and long-term adverse effect on the ability to carry out normal day-to-day activities, covering a wide range of conditions including chronic physical illness, learning disabilities, and diagnosed mental health conditions such as depression, anxiety disorders, and psychotic illnesses.

In the tax investigation context, the duty translates into practical adjustments: extended time limits to respond to enquiry letters or information notices; correspondence in an alternative format or through a specified channel (for example, avoiding telephone contact for someone whose condition makes phone calls acutely difficult); a single, consistent named contact rather than a rotating case-handling team; the option to have a nominated representative or support person present at any meeting; and adjusted formats or pacing for interviews or meetings themselves.

This runs alongside HMRC's separate "vulnerable customer" guidance, not instead of it: HMRC's Extra Support Service and vulnerable customer policies are administrative commitments sitting on top of, but not a substitute for, the underlying statutory Equality Act duty. Framing a request explicitly by reference to the Act, rather than simply asking to be treated as "vulnerable", invokes a legal obligation rather than a discretionary courtesy.

Two separate channels: HMRC itself, and the tribunal

A point that catches many taxpayers and even some advisers out: the duty to make reasonable adjustments operates on two entirely separate channels, and satisfying one does not automatically satisfy the other. During the enquiry stage, before any tribunal appeal exists, the relevant duty is HMRC's own obligation under section 20 of the Equality Act, engaged directly with the officer or team handling the case. If the matter proceeds to an appeal at the First-tier Tribunal, a fresh request needs to be made to the tribunal itself, governed by its own Practice Direction on adjustments for vulnerable parties and witnesses, generally referred to as PD1A. A reasonable adjustment agreed with HMRC during the enquiry, extended deadlines, written-only correspondence, does not automatically transfer to the tribunal once proceedings begin, and a refusal by HMRC on one channel does not excuse a taxpayer from making the parallel request on the other if their case reaches that stage.

Making an effective request

A reasonable adjustment request is far more likely to succeed, and to succeed quickly, where it is specific rather than general. A letter that says "I have anxiety and find this stressful" gives HMRC very little to act on. A letter that identifies the specific diagnosed condition, the specific way it creates a disadvantage in the specific process HMRC is using (for example, "unstructured verbal interviews are particularly difficult for me due to [condition], and I request that any interview be conducted with prepared written questions provided in advance"), and the specific adjustment requested, gives HMRC something concrete to assess and grant. Supporting medical evidence, even a short letter from a GP or treating clinician confirming the diagnosis and its practical effects, materially strengthens the request without needing to disclose exhaustive medical detail.

Requests should be made as early as possible, ideally at the very first point of contact with HMRC on a matter, rather than partway through an enquiry once deadlines have already caused difficulty. HMRC's own guidance to staff recognises the Extra Support Service as the internal route for handling these requests, and a request that explicitly references both the Equality Act duty and the Extra Support Service tends to be routed and actioned more reliably than one that does neither.

How this plays out in practice

A self-employed taxpayer with a diagnosed psychotic illness receives a standard HMRC enquiry letter with a 30-day response deadline and a request to attend an in-person meeting. Overwhelmed by the formality and the meeting request specifically, the taxpayer misses the initial deadline entirely. Once advised, a written adjustment request is submitted identifying the diagnosis, explaining that unstructured in-person meetings are a specific and significant trigger, supported by a brief letter from the taxpayer's psychiatrist, and requesting that all further communication proceed in writing with realistic extended deadlines, and that any need for a meeting be replaced with written questions wherever possible. HMRC agrees the adjustments, the enquiry proceeds by correspondence at a manageable pace, and the taxpayer is able to engage properly with the substance of the enquiry for the first time.

If HMRC refuses

A refusal, or simply HMRC proceeding without engaging with a properly made request, is not the end of the road. The first escalation route is usually HMRC's own complaints process, which can specifically address a failure to apply reasonable adjustments guidance. Where the disadvantage caused is serious, for example where HMRC has proceeded to a determination or penalty without having addressed a properly evidenced adjustment request, the underlying statutory duty under the Equality Act is capable, in principle, of supporting a judicial review challenge to that failure, though this is a significant step generally reserved for cases where lesser routes have not resolved the position and real prejudice has resulted.

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Frequently asked questions

Does HMRC have to make reasonable adjustments for disabled taxpayers?

Yes. As a public authority, HMRC is bound by the Equality Act 2010 s20 duty to make reasonable adjustments where a disabled person would otherwise be substantially disadvantaged, covering extended deadlines, adjusted communication, alternative interview arrangements and more.

How do I ask HMRC for reasonable adjustments?

In writing, identifying the specific condition, the specific disadvantage it creates, and the specific adjustment requested. Supporting medical evidence strengthens the request. Reference HMRC's Extra Support Service and the Equality Act duty explicitly.

Does a reasonable adjustment request to HMRC also cover the tribunal?

No. HMRC's duty and the tribunal's own Practice Direction 1A operate separately. A fresh request should be made to the tribunal if a matter is appealed, even where HMRC has already agreed adjustments during the enquiry.

What happens if HMRC refuses a reasonable adjustment request?

Escalate via HMRC's complaints process first. Where serious prejudice results from a failure to apply the statutory duty, judicial review is potentially available, though generally reserved for cases where other routes haven't resolved the position.