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Employer requiring medical evidence for reasonable adjustment?

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Last updated 15th August 2021 (part update 10th March, 2023).

If you tell the employer about your stammer, can the employer require medical or other evidence before making a reasonable adjustment?


If you tell the employer about your stammer and any issues for which you want reasonable adjustments, it is possible that the employer does not have to take your word for it. However the stammer and relevant effects may be evident, so that the employer actually knows about them anyway (and so would not have a legal defence). Whether or not they are evident, if the employer does want to make further enquiries I would suggest co-operating.

At the very least, telling the employer about the stammer – and any disadvantage for which you want adjustments – should put the employer on notice to investigate the position (see Constructive knowledge).

As discussed on Knowledge of disability, neither the reasonable adjustment duty nor discrimination arising from disability (EqA s,15) applies if the employer does not know and cannot reasonably be expected to know:

  • that the person has a disability and
  • in the case of the reasonable adjustment duty (not s.15), that the person is likely to be placed at the relevant disadvantage.

In summary:

  • The employer must do all it can reasonably be expected to do to find out whether the employee has a disability (and, in the case of reasonable adjustments, is likely to be placed at a substantial disadvantage).
  • The knowledge may be actual or constructive, ie what the employer would have found out had it made reasonable enquiries.
  • As regards knowledge of the disability, the knowledge required is of the facts of the disability – broadly that there is an impairment with a long-term and more than minor or trivial adverse effect on normal day-to-day activities (Gallop v Newport City Council, Knowledge of disability>Knowledge of facts of the disability, rather than law).
  • In deciding whether there is an “impairment”, the focus is on its effects – there need not be a medical diagnosis: Walker v Sita, Stammering starting in adulthood>Impairment.

On what you might tell the employer, see Recruitment: Should I tell the employer I stammer?

So is medical evidence required?

It seems an employer does not necessarily have to just take someone’s word that they have a disability:

Cox v Essex County Fire and Rescue (bailii.org), EAT, 2013
The claimant told the employer he had bipolar disorder, but medical reports seen by the employer did not give that as a confirmed diagnosis. The claimant refused access to his GP records. The claimant (allegedly) behaved in an aggressive and threatening way, but it was not clear that was related to a medical condition. The EAT upheld a finding that the employer did not have actual or constructive knowledge of the disability.

Effects of stammer evident to listeners

Often (some) effects of a stammer are evident to listeners as something different from normal speech. Such effects may well be evident to the employer (including its staff) – for example sometimes struggling to speak in meetings or on the phone, or in other work situations. “Normal day-to-day activities” includes almost any work situation, and the effect only has to be more than minor or trivial. I suggest that especially bolstered by the individual’s explanation that they have a stammer, it will normally be difficult here for an employer to argue it did not know of the disability. Similarly, disadvantages for which the person would like reasonable adjustments – such as difficulties in phone calls or meetings – may well be evident to the employer.

Even so, if the employer does want to make further enquiries, I would suggest co-operating. Examples could include the employer referring the person to Occupational Health, the individual consenting to OH getting relevant information from their GP or speech and language therapist if they have one, or the employer or OH arranging a report from a speech and language therapist with particular knowledge of stammering (who will know much more about stammering than OH or a GP). Tribunals are understandably more likely to find against a claimant who has not co-operated with the employer’s investigation. But at least if the stammer is evident, actually and legally the employer may well know of the disability and relevant disadvantage even before the investigation. So the employer may not be justified in delaying adjustments.

Hidden stammer

Sometimes the stammer is not evident to listeners. With covert stammering the stammer may even be hidden pretty much completely.

If the person tells the employer about the stammer, the employer may well take the person’s word, especially if the individual explains about hiding it and the hidden effects the stammer has.

However, if the individual does not co-operate (see above) with an employer who wants to check or just to get further advice, the individual here would be at particular risk of the employer being seen as not having actual or constructive knowledge of the disability. It is possible that the employer need not rely on the individual’s word, though how far that is so for stammering is not clear. (Could it be argued that unlike with a mental health disability as in Cox v Essex above, for stammering it is normally much easier to tell from the individual’s description that they have a disability. Also to a large extent medical professionals have to rely on what the individual tells them.)


  • Prove it: Discrimination by the Backdoor (pdf, ucl.ac.uk) – by EmployAbility, 2020, suggesting that the common practice of employers requesting neurodiverse candidates provide medical evidence of their condition, before being provided with adjustments in the recruitment process, is not permitted under the legislation.
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