- The duty arises once an employer knows, or could reasonably be expected to know, that a worker has a disability and is at a substantial disadvantage. In employment it is not anticipatory, so the process for responding has to be ready in advance.
- Whether an adjustment is reasonable turns on effectiveness, practicability, cost and disruption, the employer's resources, the help available and the size of the organisation. Most adjustments cost little or nothing.
- The law sets no fixed deadline. The duty is breached from the point at which it would have been reasonable to have made the adjustment, so unexplained delay is itself a risk.
- Confirm adjustments in writing, review them regularly, for example every six months or when something changes, and use occupational health to turn a condition into specific, workable recommendations.
Every HR manager knows the phrase, and most could recite the definition. Yet the same small failures come up in tribunal claims year after year. Nobody realised the duty had been triggered. The request sat in an inbox for four months. The adjustment was agreed but never implemented, or implemented and never reviewed. This guide is about process rather than definition. Our earlier article on what counts as reasonable covers the test. This one sets out the steps that take an employer from a first conversation to an adjustment that works and can be defended.
When the duty applies
Under the Equality Act 2010 a person is disabled if they have a physical or mental impairment that has a substantial and long-term adverse effect on their ability to carry out normal day-to-day activities. Substantial means more than minor or trivial. Long-term means the effect has lasted, or is likely to last, at least 12 months, or for the rest of the person's life, and an effect that has stopped counts if it is likely to recur. Cancer, HIV infection and multiple sclerosis are disabilities from diagnosis, and an impairment being controlled by treatment or medication is assessed as it would be without that treatment. No formal diagnosis is required, and Acas notes that not everyone who meets the legal definition will consider themselves disabled.
Section 20 sets out three requirements. Where a provision, criterion or practice, a physical feature of the premises, or the absence of an auxiliary aid puts a disabled person at a substantial disadvantage compared with people who are not disabled, the employer must take such steps as it is reasonable to have to take to avoid the disadvantage. The employer cannot pass the cost to the disabled person, and under section 21 a failure to comply is discrimination.
Two points about timing and knowledge are less well known. The duty is owed to an individual, and under Schedule 8 it does not arise unless the employer knows, or could reasonably be expected to know, that the person has a disability and is likely to be placed at the disadvantage. And, unlike the duty on shops and service providers, the employer's duty is not anticipatory. The Act's own explanatory notes say that an employer is not required to anticipate the needs of potential disabled employees or job applicants and make reasonable adjustments in advance. The practical consequence is the opposite of complacency. Because the duty bites the moment the trigger is met, the process for responding has to exist before it is needed.
The law does not ask whether you meant well. It asks whether a reasonable step was available, whether you knew it was needed, and how long it took you to take it.
Step 1: recognise the trigger
The trigger is rarely a formal request that says "reasonable adjustment". It is a fit note that suggests amended duties. A pattern of short absences with the same cause. A disclosure at a return-to-work meeting. A manager noticing that someone who used to cope no longer does. A GP letter. What the employer could reasonably be expected to know is judged across the organisation, so absence records, return-to-work notes and what line managers have been told all matter.
When there are signs, ask. Acas advises employers to arrange a meeting, listen to the person, try to understand how their disability affects them at work and not make assumptions. Nobody has to tell their employer they are disabled, but once they do, or once the employer ought to have realised, the responsibility to support them is legal rather than discretionary.
Good practice
Do not wait for a diagnosis. Acas is explicit that a worker does not need a diagnosis to be considered disabled under the Act, and NHS waiting lists mean the letter may be many months away. Respond to the difficulty the person is actually experiencing.
Step 2: have the conversation
The most reasonable first step is almost always to ask the person what would help. They know their condition and their job better than anyone, and Acas's guidance on reasonable adjustments is built around that meeting. Prepare for it by understanding the role's real demands. In the meeting, cover how the condition affects the person at work, which tasks and times of day are hardest, what they have already tried, what they think would help and how urgently. Agree what will happen next and when.
Some organisations use a reasonable adjustments passport, a record kept by the employee of how their disability affects them, the adjustments agreed and what they may need in future, so that a change of manager does not mean starting again. The DWP publishes a Health Adjustment Passport that serves the same purpose and links to Access to Work.
Step 3: get advice where you need it
For a simple request, the conversation may be enough. Where the condition is complex, fluctuating or unfamiliar, where the role is safety-critical, or where the person and the manager disagree about what is possible, occupational health advice turns a diagnosis into specific recommendations. Acas suggests the employer could agree with the worker to get an occupational health assessment when it needs help to decide what adjustments are needed. A management referral that asks what the person's functional limitations are for the key parts of the role, what adjustments would help and for how long, and whether the Act is likely to apply, will get an answer a manager can act on. For mental health and neurodiversity, a workplace needs assessment does the same job in more depth.
Then consider funding. Access to Work is a government grant that can pay for specialist equipment and software, support workers, travel to work where public transport cannot be used, and mental health support. The employee applies, the grant does not have to be repaid, and it will not pay for the reasonable adjustments an employer is legally required to make. Larger employers may be asked to share the cost of aids, equipment and adaptations. Where cost sharing applies, the employer pays the costs up to a threshold of £500 (50 to 249 employees) or £1,000 (250 or more) and 20% of the costs between that threshold and £10,000, with the balance normally met by the grant; check the current DWP factsheet for how the scheme treats smaller employers. The scheme has been carrying a substantial backlog, with around 60,000 applications awaiting a decision in May 2026, so build the waiting time into your plan and put interim measures in place.
Step 4: decide what is reasonable
The Act does not define reasonable, but the EHRC's statutory code of practice on employment lists the factors. Whether the step would be effective in preventing the disadvantage. How practicable it is. The financial and other costs and the extent of any disruption. The employer's financial and other resources. The availability of financial or other assistance such as Access to Work. And the type and size of the employer. The code also observes that effective and practicable adjustments often involve little or no cost or disruption and are therefore very likely to be reasonable. GOV.UK's guidance for employers makes the same point.
The code's examples cover the ground most employers will meet. Reallocating some duties to another person, transferring the person to an existing vacancy, altering hours or place of work, allowing absence for rehabilitation or treatment, acquiring or modifying equipment, modifying procedures for testing or assessment, and providing supervision or other support. Adjustments to the absence process itself, such as adjusted trigger points or recording disability-related absence separately, are also well established.
Where an adjustment is not reasonable, Acas is clear that the employer does not have to make it, but should talk with the person, explain the decision and find another way to support them. Record the reasoning. Ultimately whether an adjustment was reasonable is a matter for an employment tribunal, and a documented, evidence-based decision is the best answer to that question.
Step 5: confirm it in writing and make it happen
Acas advises confirming any agreed adjustments in writing, in a letter or email. State what has been agreed, who is responsible for putting each element in place, by when, and when it will be reviewed. Brief the people who need to know, and only those people, since health information is special category data. Then check that it has actually happened. An adjustment that exists in a letter and not on the floor is a common fact pattern in claims.
How long does an employer have to make reasonable adjustments?
The law sets no fixed period. Research published by the government's Office for Equality and Opportunity in September 2026 states in terms that the Equality Act does not specify the amount of time an employer should take. The test is reasonableness. The Employment Appeal Tribunal held in Fernandes v Department for Work and Pensions in 2023 that the duty arises as soon as there is a substantial disadvantage, and that failure to make the adjustment becomes a breach once it becomes reasonable for the employer to have to make it. For time-limit purposes, the Act itself treats a failure to act as occurring at the end of the period in which the employer might reasonably have been expected to act.
So delay is measured against what was reasonable in the circumstances, and delay beyond that point, with no good reason, is itself a failure to make the adjustment. The same government research cites a TUC survey in which 82% of disabled employees waited four months or more for their adjustments to be implemented. Four months for a chair or a change of start time would be hard to defend.
Our suggestion is to acknowledge a request within days, put interim measures in place immediately where you can, decide simple adjustments within a week or two, and for complex cases move at the pace of the advice you need, which at Medwyn means an appointment within five working days and a report within 72 hours. Record the reason for any delay that is outside your control, such as a wait for Access to Work.
One procedural change is worth noting. For acts occurring on or after 1 October 2026, the time limit for bringing most employment tribunal claims, including discrimination claims, rises from three months less a day to six months less a day under the Employment Rights Act 2025. Compensation for discrimination remains uncapped.
Step 6: review, and keep reviewing
Conditions change, roles change and adjustments stop working. Acas suggests that anyone with reasonable adjustments should talk with their manager regularly, for example every six months or if something changes. Build the review into the written agreement, ask whether the adjustment is still doing its job, and be willing to change it. For fluctuating conditions, HSE's advice is to keep making adjustments so that a return to work stays sustainable. If the manager changes, the passport or the written record should follow the employee.
The process in one place
- Recognise the trigger, including fit notes, absence patterns and disclosures, and act on what the organisation could reasonably be expected to know
- Meet the person, listen, ask what would help and agree next steps with dates
- Get occupational health or workplace needs advice where the answer is not obvious, and consider Access to Work funding
- Decide what is reasonable using the statutory code's factors, and explain and record any refusal
- Confirm the adjustment in writing with responsibilities, deadlines and a review date, then check it has happened
- Act without unexplained delay, using interim measures while advice or funding is awaited
- Review regularly, for example every six months or when something changes, and keep the record with the employee
Most adjustments are small, cheap and quick, and most of the risk lies in the process around them rather than the adjustment itself. If you have a case where the right adjustment is not obvious, or a request has stalled, a management referral will give you specific, work-focused advice and a timescale to act on.
This article is general guidance for employers and is not individual medical or legal advice. If you are unsure how it applies to your organisation, contact our team.
