Complaint Evidence Checklist

Complaints are decided on the record, not on how strongly you feel about what happened. An ombudsman or adjudicator who has never met either of you will read the paperwork and reach a view, so the organised complaint with a clear chronology beats the angry one almost every time. The evidence you need is also easiest to collect while events are fresh and while you still have access to accounts and apps. Use this checklist before you escalate.

Collect it while you still can

Start gathering from the moment the problem appears, not when you decide to escalate. Chat transcripts vanish when an app updates, online accounts close when a contract ends, and nobody remembers the name of the person they spoke to three months later. Five minutes of note-taking after each call is worth more than an hour of reconstruction afterwards.

  • The final response or deadlock letter is the item most schemes cannot proceed without. If the organisation has gone quiet instead, note the date you complained — after the scheme's waiting period you can usually refer anyway.
  • A timeline of events does more work than any other single document. One line per event, dated, in order, with a reference to the document that proves it.
  • Evidence of what it cost you turns a grievance into a claim. Keep receipts for anything you had to buy, replace or repair because of the problem.

Missing items do not always sink a complaint, but they shift the balance. Where it is your word against a call handler's and you have no note of the conversation, the organisation's own record usually prevails. Where you have dates, names and a contemporaneous note, it does not.

Watch the time limits. Most schemes measure the deadline from the organisation's final response, and it is shorter than people assume. Gather what you can, refer within the limit, and send anything further afterwards — waiting for one last document while the deadline passes is the worst possible outcome.

Communication records

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Financial evidence

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Supporting evidence

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Helpful organisations

Financial Ombudsman Service

Ombudsman

Resolves complaints between consumers and financial businesses such as banks, insurers, and lenders.

Visit website0800 023 4567

Energy Ombudsman

Ombudsman

Resolves complaints between energy consumers and suppliers, including gas and electricity companies.

Visit website0330 440 1624

Citizens Advice

Charity

Provides free, confidential, and independent advice on a wide range of issues including benefits, housing, debt, and employment.

Visit website0800 144 8848

Frequently asked questions

What if the company will not give me a final response?
You do not always need one. Most schemes let you refer a complaint once a set period has passed since you complained — commonly eight weeks — without an adequate response. Keep proof of when and how you complained, such as a sent email, a recorded delivery receipt or a case reference. Send a short chaser saying you will escalate if you do not receive a final response by a stated date, then refer. Silence is not a defence for the organisation.
Can I get copies of my own records from the company?
Yes. A subject access request under data protection law requires an organisation to give you the personal data it holds about you, which typically includes call recordings, internal notes, account history and correspondence. It is free and must normally be answered within a month. Ask specifically for what you need rather than everything, or you will receive an unmanageable bundle. Internal notes often reveal more about what really happened than the customer-facing correspondence does.
How much detail should my complaint actually contain?
Enough to be clear and no more. Investigators handle large caseloads, so a short covering summary saying what went wrong, what it cost you and what you want, followed by a dated timeline and numbered attachments, is far more effective than a long narrative. Leave out how frustrating the experience was and concentrate on facts and dates. State the outcome you are seeking specifically — a refund figure, a correction, an apology — rather than leaving it open.
Does complaining stop the company chasing me for payment?
Not automatically. In some regulated sectors an organisation should suspend collection activity on a disputed amount while a complaint is investigated, but this is not universal, and interest may continue to accrue. Ask explicitly for the disputed sum to be put on hold and get the answer in writing. If a disputed debt is passed to a collection agency or reported to credit reference agencies while your complaint is live, add that to the complaint as separate detriment.

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Disclaimer

This information is for general guidance only and does not constitute legal, financial, or professional advice. Always check official sources and seek qualified help where needed.