How to write a formal complaint

The person who reads your complaint did not cause the problem, is handling forty others, and is working from a script that tells them what they are allowed to offer. Everything about how you write follows from that.

Anger is legitimate and it is also counterproductive on paper. A furious letter gets a template reply. A dated, specific, unemotional letter that names exactly what you want is the one that gets escalated, because it is the one that is easy to act on.

The structure

Your details and theirs. Name, address, email, phone. Account, order, policy or case number in a reference line at the top — this is how your letter gets attached to your record instead of floating loose.

One line on what this is. "I am writing to complain about a washing machine delivered damaged on 14 August 2026 and not yet replaced."

What happened, in dated order. This is the core. Dates, times, names of people you spoke to, reference numbers of previous calls. No adjectives. Not "your appalling service" but "I called on 16 August and was told a replacement would arrive within five working days. It did not."

Why it is wrong. Briefly. The goods were faulty; the service was not what was described; the policy was not followed.

What you have already tried. Every previous contact, dated. This is what proves the complaint is not new and justifies escalation.

What you want. Be specific, be reasonable, and be one thing. "A full refund of ₦185,000" or "a replacement delivered by 30 September". Vague dissatisfaction gives them nothing to approve. Asking for the moon gives them a reason to refuse.

A deadline. Fourteen days is standard and reasonable.

What you will do next. Stated plainly, not as a threat: the ombudsman, the regulator, the small claims process, a chargeback. Naming the actual next step is the single most effective sentence in most complaints, because it tells the reader this will not simply go away.

Enclosures. List them. Receipts, photographs, previous correspondence.

Tone

Cold and factual outperforms angry every time. Do not use capitals, exclamation marks or sarcasm. Do not say you will "never use them again" — they have your money already and it costs them nothing.

Do not threaten anything you will not do. If you say ombudsman, know that the ombudsman exists for that sector and that you have exhausted the internal process first, which is usually required.

One page. Two only if the timeline genuinely needs it.

Getting it to the right person

Complain in writing, even if you started by phone, and keep a copy. Email creates a timestamp; recorded delivery creates proof. Address it to the complaints department if there is one, and to a named senior person if you can find one and the first round has failed.

Most organisations have a formal internal complaints procedure with defined stages, and most external bodies will not look at your case until it is finished. Ask for a copy of the procedure in your first letter — it costs you one sentence and it starts the clock.

Common mistakes

Writing while angry and sending it the same hour. No dates. No reference numbers. Three complaints in one letter, so none is resolved. Not saying what you want. Threatening legal action you will not take. Complaining only by phone, leaving no record. Going public before the internal process is finished, which some organisations use as a reason to stop engaging.

Practical tips

• Write it, then leave it overnight, then cut every adjective.
• Keep a single file with every call date, name and reference number as it happens.
• Photograph damage immediately, with something for scale.
• If the first reply is a template, reply once asking for the complaints procedure and the reference number, then escalate.
• Check whether a statutory time limit applies to your kind of complaint before you let it drift.