Tell HR or your manager first? The post-diagnosis decision tree.

The manager route feels right. Your manager is the person you work with every day. They already know how your dyslexia affects your output, even if neither of you had a name for it before. A conversation with them feels natural.

But "natural" and "legally effective" aren't the same thing here. The route you take when you disclose your diagnosis affects whether you end up with enforceable adjustments on a clear timeline, or a sympathetic conversation that leads nowhere for six weeks.

The legal question: who counts as "the employer" when the duty to act is triggered?

What "employer knowledge" means under UK law

Sections 20 and 21 of the Equality Act 2010 set out the duty to make reasonable adjustments. The duty is triggered when the employer knows, or could reasonably be expected to know, that the employee has a disability that creates a substantial disadvantage.

"Knows" means the information has reached someone whose knowledge can be attributed to the organisation. HR has formal authority for employment records and adjustment procedures. Their knowledge is unambiguously employer knowledge.

A line manager's knowledge is also generally attributed to the employer. UK employment tribunals have found this consistently. But there's a practical problem: a manager who knows about your diagnosis without documenting it can't be easily proved to have known, particularly if that manager later leaves or denies the conversation happened.

The "ought reasonably to know" test catches employers who didn't ask the right questions, but it's not a substitute for documentation. If there's no record that the employer was told, the tribunal argument becomes a question of credibility, yours against the employer's.

An email changes that. It creates a timestamp, a record of what was said, and proof that the duty was triggered from a specific date.

The choice between HR and manager is a choice about evidence. Your manager's sympathy doesn't create a paper trail. An email to HR does.

Going to HR first: what actually happens

You send an email. It doesn't need to be detailed. "I have a dyslexia diagnosis and would like to discuss what reasonable adjustments might be appropriate for my role" is sufficient. That email triggers several things.

First, the duty to make reasonable adjustments is officially on the clock from that date. If HR does nothing for three months, you have documentation of three months of non-compliance.

Second, HR should follow ACAS procedure. Under ACAS guidance (updated January 2025), once an adjustment request is made, the employer should arrange a meeting, take the lead from the employee about what adjustments are needed, and confirm any agreed adjustments in writing. HR is the function most likely to know that procedure exists.

Third, if your employer has an occupational health referral process, HR can initiate it. An occupational health report documenting your dyslexia and recommending specific adjustments is hard for a line manager to ignore or forget.

Keep a copy of your disclosure email and every response. If you're using a work account, forward the thread to your personal email address after sending. Tribunal claims can follow you out of a job.

If your employer has a specific formal disclosure process, ask HR for it before sending a freeform email. Following the prescribed route strengthens your position because it closes the argument that the disclosure wasn't handled through the right channel.

A written HR disclosure is the minimum record you need. Everything that comes after it, meetings, adjustment plans, equipment orders, can be traced back to that starting point.

Going to your manager first: when it works and when it doesn't

Some managers are genuinely excellent at this. They know their team, they act quickly, and they make the conversation easy. Starting with them isn't wrong, as long as you back it up in writing on the same day.

The pattern that causes problems: verbal conversation with a sympathetic manager, followed by nothing in writing, followed by a gradual drift back to normal working conditions, followed by a performance review three months later where none of the adjustments you needed were in place.

The manager assumed the informal arrangement was enough. You assumed they'd followed up with HR. Nobody kept a record. You're now trying to explain, in a formal meeting, why your output fell short, without documentation that adjustments were ever formally requested.

If you've already had the manager conversation, fix it today. Send an email to your manager, copy HR, and state three things: the conversation took place, you have a dyslexia diagnosis, and you'd like to formally begin the adjustments process. That email creates the record that was missing from the conversation.

The reasonable adjustments builder can help you turn your specific difficulties into a written request: it takes around two minutes and produces a draft email you can send directly to HR or copy into the follow-up.

A manager-first conversation is fine. A manager-first conversation with no written follow-up is a liability. If you've told your manager and nothing is confirmed in writing, fix that today.

Where occupational health fits in

Occupational health (OH) is separate from HR and separate from your manager. It provides independent medical advice on what adjustments are clinically appropriate. It's a useful step, but it's not a prerequisite.

Your employer does not have to wait for an OH report before making adjustments. If you disclose your diagnosis and ask for additional time for written tasks, an employer who says "we need to wait for occupational health" before agreeing to anything is likely breaching the duty. Reasonable adjustments with low cost and low complexity should start immediately after disclosure.

An OH referral makes sense for more complex adjustment cases: roles with physical requirements, jobs where multiple adjustments interact, or situations where the employer needs documented advice to satisfy their board or HR department. If your employer proposes one, it's usually worth cooperating. An OH report that formally recommends software, time extensions, or format changes gives you a second source of documentation.

You can decline an OH referral, but declining means the employer may have less information to act on. In a dispute, "we couldn't get the employee to engage with OH" can be used to argue that the employer did what they could. Cooperation is usually in your interest.

Occupational health is one useful step in the process, not the trigger for it. Disclosure in writing to HR starts the clock. OH comes after, when it's needed.

The US position: HR and the ADA interactive process

In the US, the ADA requires employers to engage in an "interactive process" once an accommodation request is made. An employee can request an accommodation without naming the ADA and without submitting a formal diagnosis, as long as they tell the employer they have a disability-related need. The EEOC has confirmed this: plain English is enough.

Going to HR in writing triggers the interactive process formally. The employer must then engage in a genuine back-and-forth about what accommodations would allow you to do the job. Refusing to engage with the process, not just refusing the accommodation, is itself an ADA violation.

Your employer can request documentation of the disability to support the accommodation request. A diagnostic report from a neuropsychologist or educational psychologist is the standard evidence. If you don't have a formal diagnosis yet, the Job Accommodation Network (askjan.org) has guidance on how to initiate a request and what documentation employers can and can't require.

HR documentation matters as much in the US as in the UK. An undocumented verbal request to a line manager gives the employer room to argue the interactive process was never properly triggered.

US employees: an email to HR, in plain English, starts the ADA interactive process. Your employer then has to engage. An undocumented verbal request doesn't carry the same weight.

The call: what to do by situation

Here's the recommended sequence, by where you are right now.

You've just been diagnosed and haven't told anyone at work yet. Send an email to HR today. Keep it short: state your diagnosis, say you'd like to discuss reasonable adjustments, and ask them to acknowledge receipt. Then tell your manager, in a separate email or in person on the same day. The HR email is the formal starting point. The manager conversation is a working relationship conversation.

You've told your manager informally and nothing is confirmed in writing. Send the follow-up email now. Address it to your manager and copy HR. Confirm the conversation took place, state your diagnosis, and request that the formal adjustments process begins. Keep the tone professional and specific: "Following our conversation on [date], I wanted to confirm in writing that I have a dyslexia diagnosis and would like to formally request reasonable adjustments."

You're in an organisation with a formal disability disclosure process. Ask HR for the right form or procedure before sending anything. Following the official route closes the argument that the disclosure wasn't handled through the right channel. Get the procedure in writing before you start it.

Your relationship with your manager is difficult, or you're concerned about their response. Go straight to HR. You have no obligation to inform your manager before informing HR. HR has confidentiality obligations under UK GDPR and the Data Protection Act 2018. They'll tell your manager that a disclosure has been made and that the adjustments process needs to start, without sharing more than necessary.

Once the process is running, the Access to Work calculator is worth checking. Access to Work can fund text-to-speech software, specialist coaching, workplace needs assessments, and other adjustments on top of what your employer provides. Knowing what's available before the HR meeting means you're coming in with a specific list, not waiting for them to suggest things.

Your situation	First step	Follow-up
Just diagnosed, nobody at work knows yet	Email HR today	Inform manager same day, in person or by email
Told manager informally, nothing in writing	Follow-up email to manager + CC HR	Confirm diagnosis, date of conversation, request formal process
Formal disclosure process exists at your organisation	Ask HR for the procedure, then follow it	Keep a copy of everything; confirm receipt in writing
Manager relationship is difficult or uncertain	Email HR only, initially	HR informs manager as needed under confidentiality obligations

One thing worth knowing before you send that email: the disclosure decision guide covers in-employment disclosure in detail, including scripts for different scenarios, a checklist of what to include in the email, and guidance on what to do if HR acknowledges but doesn't act.

The adjustments you ask for matter as much as the disclosure itself. Vague requests ("I'd like some support with my dyslexia") are harder to enforce than specific ones ("I'd like written instructions for all verbal briefings, additional time for written tasks, and access to text-to-speech software"). The adjustments builder generates a specific, costed list based on your role and the tasks you find hardest.

The disclosure sequence matters less than the paper trail. Whatever order you tell people, confirm the disclosure in writing to HR. An email with a timestamp is what you'll rely on if adjustments are delayed, refused, or forgotten.

If nothing happens after you disclose

The legal duty is triggered. But the duty doesn't automatically produce an adjustment plan. In some organisations, a disclosure email starts a formal process that runs within weeks. In others, it disappears into someone's inbox.

If you've disclosed in writing and haven't had a meaningful response within two weeks, send a follow-up email. Keep it factual: "I wrote to you on [date] to disclose my dyslexia diagnosis and request reasonable adjustments. I haven't yet received confirmation of next steps. Could you let me know the timeline?" That email creates a second timestamp showing the delay.

If you're still getting no response after a further two weeks, you have two routes. The first is to raise a formal grievance under your employer's grievance procedure, citing the failure to engage with an adjustment request. The second is to contact ACAS (0300 123 1100) for free early conciliation advice before any tribunal claim.

Disability discrimination claims for failure to make reasonable adjustments carry uncapped compensation in UK employment tribunals. In the US, EEOC complaints and ADA claims carry compensatory and punitive damages capped by employer size, with uncapped back pay. Employers who ignore a written adjustment request are building a legal liability, not avoiding one.

A written disclosure with no response from the employer is the starting point for an enforcement action, not the end of the conversation. Keep the paper trail and escalate if weeks pass with no engagement.