Last reviewed March 2026 — LetterSure editorial team
A well-written complaint letter is one of the most effective ways to resolve a dispute with a company. Here is exactly how to write one that gets taken seriously — and what to do if they ignore it.
A formal written complaint is more effective than a phone call for several reasons. It creates a paper trail, gives the company a clear deadline to respond, and shows you are serious about escalating if they do not resolve the issue. If you later need to go to an ombudsman or raise a chargeback, having a written complaint on record strengthens your position significantly.
Most companies take written complaints more seriously than calls or online chat because they know a written complaint can be escalated. A professional, factual letter often gets results where informal complaints have failed.
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Generate my complaint letter — £6.99Your name and contact details
Include your full name, address, email, and phone number so the company can respond.
Your account or order reference
Include any reference number so the company can locate your account quickly.
A clear description of what went wrong
Be specific — what happened, when it happened, and who was involved.
How it has affected you
Explain the impact — financial loss, inconvenience, distress, or time wasted.
Previous attempts to resolve it
Mention any calls, emails, or online chats you have already had and what was said.
What outcome you want
Be specific — a refund, an apology, a repair, compensation, or a combination.
A deadline
Give the company 14 days to respond before you escalate.
Always try to address your complaint to a named person — the customer services manager, complaints manager, or CEO for smaller businesses. A letter addressed to a named individual is more likely to be taken seriously than one addressed to a generic department. Check the company website or call their main number to find the right name.
For large companies, addressing your letter to the CEO and copying in the customer services team is a technique that often gets faster results. CEOs rarely read complaint letters personally but their PA will escalate it to the right team — and letters that have landed on the CEO's desk tend to get prioritised.
Firm, factual, and professional. Angry or emotional letters are easier for companies to dismiss. A calm letter that sets out the facts clearly, states what you want, and makes clear you know your rights is far more effective. Do not make threats you are not prepared to follow through on — but do make clear you are aware of your right to escalate to an ombudsman or regulator.
Send a follow-up letter referencing your original complaint and stating you will now escalate. Escalation options depend on the sector — energy and telecoms have their own ombudsmen, financial services companies are regulated by the Financial Conduct Authority, and retailers can be taken to the relevant Alternative Dispute Resolution scheme.
If you paid by credit card you can raise a Section 75 claim with your card provider for purchases over £100. For debit card payments, request a chargeback through your bank. Citizens Advice can help you identify the right escalation route for your specific situation.
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How do I write a complaint letter to a company?
Include your name and contact details, account reference, a clear description of what went wrong, how it affected you, previous attempts to resolve it, what outcome you want, and a 14 day deadline. Keep your tone firm but professional.
Who should I address a complaint letter to?
Always try to address a named person — the customer services manager, complaints manager, or CEO for smaller businesses. A named letter is more likely to be taken seriously than one addressed to a generic department.
What happens if a company ignores my complaint?
Send a follow-up referencing your original and stating you will escalate. Escalation options include the relevant ombudsman, a Section 75 claim with your credit card provider, or a chargeback through your bank.
How long does a company have to respond to a complaint?
14 days is considered reasonable. Financial services companies must acknowledge within 5 business days and provide a final response within 8 weeks under FCA rules.
Should I email or post my complaint letter?
Either is acceptable. Email is faster and gives you a timestamp. Post is more formal. For important complaints, email and keep a copy — this gives you proof of when you sent it if you need to escalate.
This guide is for general information only. LetterSure letters are personal correspondence drafts and do not constitute legal advice. For legal matters consult a qualified solicitor at solicitors.lawsociety.org.uk.