How to use ChatGPT to write a complaint letter (UK, free prompts)
Wrong energy bill? Broadband that keeps dropping out? A faulty washing machine or a delayed flight? A free AI chatbot can turn your notes into a firm, polite complaint letter in a couple of minutes. This guide shows you how, with copy-and-paste prompts, what to keep private, and where to go in the UK if the company won't put things right.
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Why use AI for a complaint?
When you're cross, it's hard to write a calm letter. A chatbot is good at taking a jumble of facts and feelings and turning them into something clear and polite but firm – the kind of letter that gets taken seriously. It can also shorten a long rant, put events in date order and suggest what to ask for.
What it can't do is know the facts of your case, or be relied on for the law. You stay in charge: AI drafts, you check.
Before you start: gather the facts
- Who you're complaining to – the company, council or landlord, and their complaints email or address (usually on their website or your bill).
- Your reference – account, customer, order or booking number. You'll add this to the letter yourself (see below).
- What went wrong, with dates – when it started, when you reported it, who you spoke to, and any reference numbers they gave you.
- Evidence – photos, receipts, bills, screenshots, emails and meter readings.
- What you want – a refund, a repair or replacement, a corrected bill, compensation, an apology, or simply for the problem to be fixed.
- A reasonable deadline for a reply, such as 14 days.
Jot these down as rough notes. They don't need to be neat – that's the chatbot's job.
What never to paste into the chatbot
Your letter will need some personal details, but the chatbot doesn't. Leave these out and add them yourself after drafting:
- Passwords, PINs and security answers.
- Bank account numbers, sort codes and card numbers.
- National Insurance, passport or NHS numbers, and your date of birth.
- Your full name and home address together.
- Other people's private details.
Tip: use placeholders. Type [MY NAME], [ACCOUNT NUMBER] and [MY ADDRESS] in the chatbot. When you're happy with the draft, copy it into your own email or Word document and swap in the real details there.
A real company will never need your password or full card details in a complaint letter. More on staying private in our AI safety guide.
Step by step with a free chatbot
- Open a free chatbot, such as ChatGPT, Microsoft Copilot or Google Gemini. The free versions are fine for this. New to chatbots? Start with our beginner's guide to ChatGPT.
- Paste in the main prompt below with your notes, using placeholders for private details.
- Ask for changes, for example “make it shorter”, “a bit firmer” or “less formal”.
- Ask it to list every fact it has included, so you can check each one against your notes.
- Copy the draft into your own email or document, add your real details, and read it once more.
- Send it through the official complaints route – the complaints email, web form or address the organisation gives. Keep a copy and write down the date you sent it.
The main prompt (copy and paste)
Copy this, fill in the [brackets] and send:
“Write a formal complaint letter in plain British English to [company or organisation]. Make it polite but firm, and no longer than one page. Use these facts only: [paste your notes – what happened, with dates, what you've already done and any reference numbers they gave you]. I want them to [what you want – e.g. refund £X, fix the fault, correct my bill]. Ask for a written reply within 14 days. Put the events in date order with short paragraphs. Use [MY NAME], [MY ADDRESS] and [ACCOUNT NUMBER] as placeholders. Do not invent any facts, dates, amounts, laws or regulations. If something is missing, leave a [bracket] for me to fill in.”
Then add: “Now list every fact, date and amount in the letter so I can check them.”
Prompts for common UK complaints
Add one of these to the main prompt, or use it on its own with your notes:
- Energy supplier (wrong or estimated bill): “My [gas/electricity] bill for [dates] is £[amount], based on estimated readings. My actual meter reading on [date] was [reading] and I've attached a photo. Ask them to re-bill me using the real reading and confirm the corrected balance.” Not sure what your bill means? See our guide to understanding your energy bill with AI.
- Broadband or mobile provider: “My broadband has been cutting out since [date]. I reported it on [dates], reference [number], and it still isn't fixed. Ask for the fault to be fixed by a set date and for a credit on my bill for the days it didn't work.”
- Shop or online retailer (faulty goods): “I bought a [item] from [retailer] on [date] for £[price]. It developed a fault on [date]: [describe fault]. Ask for a [refund/repair/replacement]. Don't quote any laws – I'll add that myself.”
- Council: “Write a complaint to [council name] about [missed bin collections / a dangerous pothole / a council tax error] since [date]. I reported it on [dates], reference [number]. Ask them to treat this as a formal complaint under their complaints procedure.”
- Landlord or letting agent: “Write to my landlord about [damp and mould / a broken boiler] which I first reported on [date]. Describe the effect on my household, ask for a date when the repair will be done, and keep a calm, firm tone.”
- Airline (delayed flight): “Write a claim to [airline] for my flight [flight number] from [airport] to [airport] on [date], which arrived about [X] hours late. Ask for any compensation I'm entitled to under UK261, plus my receipts for food of £[amount]. Keep it short and factual.”
Check the draft before you send
- Facts first. Check every date, amount, name and reference number against your notes and paperwork.
- No made-up law. Chatbots can invent rules, case names and “regulation numbers” that sound real. Delete anything you haven't checked on GOV.UK, Citizens Advice or the ombudsman's own site.
- No threats or exaggeration. Stick to what happened and what you want. Calm and specific works better than angry.
- Keep it short. One page, or a short email, is plenty. Attach evidence rather than describing it at length.
- Sounds like you? Change any phrases you wouldn't use. The Financial Ombudsman Service, for one, says it helps to hear what happened in your own words.
- Keep records. Save a copy of what you sent, the date, and any replies. You'll need them if you escalate.
If they don't put it right: where to go in the UK
Most organisations must give you a chance to use their own complaints process first. If that doesn't work, these are the main free routes. Time limits and rules can change, so check the official website before you apply.
- Energy (gas and electricity): the Energy Ombudsman is free. You usually need to give your supplier 8 weeks to sort it out, or less if they send you a “deadlock letter” saying they can't help further. (In Northern Ireland, contact the Consumer Council for Northern Ireland.)
- Phone, broadband and mobile: every provider must belong to an Ofcom-approved scheme – either the Communications Ombudsman or CISAS. Your provider's website or bill says which. For complaints first made on or after 8 April 2026 you can usually go after 6 weeks (it used to be 8), or sooner with a deadlock letter.
- Banks, credit cards, loans and insurance: the Financial Ombudsman Service is free. The firm usually has up to 8 weeks to send a final response (less for some payment and scam complaints). You normally have 6 months from that final response to go to the ombudsman.
- Councils: in England, the Local Government and Social Care Ombudsman can look at most council services once you've been through the council's own complaints process. It normally expects you to complain within 12 months of finding out about the problem. In Scotland, Wales and Northern Ireland, contact the Scottish Public Services Ombudsman, the Public Services Ombudsman for Wales or the Northern Ireland Public Services Ombudsman.
- Landlords: if you rent from a council or housing association in England, you can go to the Housing Ombudsman Service after using your landlord's complaints process. Private renters in England don't have an ombudsman yet (a new one is planned), but your council's housing or environmental health team can look at serious hazards such as damp and mould. Shelter and Citizens Advice give free advice.
- Faulty goods from a shop or website: under the Consumer Rights Act 2015, if something you bought is faulty you generally have 30 days to reject it for a full refund. After that, the seller usually gets one chance to repair or replace it, and if that fails you can ask for a refund or a price reduction. If you paid by credit card, you may also be able to claim from your card provider (Section 75 covers many purchases over £100); for debit cards, ask your bank about a chargeback.
- Flight delays: under UK261, if you arrive more than 3 hours late you may be able to claim fixed compensation – at the time of checking, £220, £350 or up to £520 per person depending on the distance – unless the delay was caused by “extraordinary circumstances” such as extreme weather. Claim from the airline first. If it says no, or doesn't reply within 8 weeks, you can go to the dispute scheme the airline belongs to, or to the Civil Aviation Authority if it isn't in one.
Free advice: the Citizens Advice consumer helpline is 0808 223 1133 (England and Wales; Welsh language 0808 223 1144). In Scotland, contact Advice Direct Scotland at consumeradvice.scot. In Northern Ireland, call Consumerline on 0300 123 6262.
Watch out for refund and complaint scams
- Ombudsman services are free. You don't need to pay anyone to complain for you. Claims companies may take a share of any money you get back.
- Be wary of cold calls, texts and emails offering refunds or compensation – especially if they ask for your bank details or a fee to “release” the money. Hang up and contact the company on a number you know.
- Never give a caller remote access to your computer or phone to “process a refund”.
More on spotting AI-powered scams is in our AI safety guide.
Frequently asked questions
Can AI write a complaint letter for me?
Yes. Free chatbots such as ChatGPT, Microsoft Copilot and Google Gemini can turn your notes into a clear, polite and firm complaint letter or email in a minute or two. You still need to give it the facts, check every line, and add your private details yourself before you send it.
Is it safe to use ChatGPT for a complaint letter?
It is fine as long as you keep sensitive details out. Never type passwords, PINs, bank or card details, or your National Insurance number into a chatbot. Use placeholders such as [ACCOUNT NUMBER] in the chatbot, then fill in the real details in your own email or document.
Will the company know I used AI?
Possibly, and that is fine – what matters is that the letter is accurate, polite and clear. Read it through, take out anything that does not sound like you, and make sure every date and amount is correct. The Financial Ombudsman Service has said it is helpful to hear what happened in your own words, so keep it simple and true.
Can AI tell me my legal rights?
It can give you a starting point, but chatbots sometimes get the law wrong or make up rules and case names. Check anything legal on GOV.UK, Citizens Advice or the relevant ombudsman's website before you put it in a letter.
How long should I wait before going to an ombudsman?
It depends on the sector. For energy, you usually need to give the supplier 8 weeks, or less if they send a deadlock letter. For phone and broadband complaints first made on or after 8 April 2026, it is usually 6 weeks. Banks usually have up to 8 weeks. Check the ombudsman's own website for the exact rules.
Do I need to pay a claims company?
Usually not. Ombudsman services such as the Energy Ombudsman, Communications Ombudsman, CISAS and the Financial Ombudsman Service are free to use, and you can claim flight delay compensation directly from the airline. Claims companies often take a share of any money you get back.