Guide
How to write a formal complaint letter at work
A complaint letter does two jobs: it explains clearly what happened, and it creates a record dated before anything else that follows. Here is the structure that does both. General information about the process — not legal advice.
A subject line that says what it is
'Formal complaint — reallocation of duties, 12 August 2025'. One line tells the reader the topic and the date without opening the letter.
An opening that states your purpose
Two sentences: who you are, and that you are making a formal complaint about a specific matter. Say which policy you are using if you know it.
A dated account of what happened
Numbered points, in order, each with a date and the people involved. Anything you cannot date, say so rather than guessing.
The effect it has had
Short and honest — on your work, your standing, your health. Keep it in its own paragraph.
What you want to happen
The single most overlooked section. Set out two or three specific, achievable outcomes so the reader knows what resolving it looks like.
Evidence and a closing request
List what you can provide, then ask for written acknowledgement and a meeting date. Sign off formally and keep a copy.
Informal or formal?
- • Informal first is usually best when the issue is recent, one-off, and likely to be a misunderstanding.
- • Go formal when informal attempts have failed, the behaviour is repeating, or you need a written record.
- • Go formal straight away when the matter is serious — for example alleged discrimination, safety, or a risk to your job.
- • A formal complaint at work is normally called a grievance, and your employer's grievance policy sets out how it will be handled.
See it written out in full
Our free sample uses a made-up scenario to show every section in place.