When something you have bought or paid for goes wrong, a clear written
complaint is usually the fastest way to put it right – and it gives you
a record you can rely on later. A good letter or email is not about sounding
legal or aggressive; it is about stating plainly what happened, which right
you are relying on, and exactly what you want the business to do. This guide
explains what every effective complaint contains and walks through the letters
most consumers need to send.

What every good complaint letter contains

Whether you write to a shop, a tradesperson, an insurer or a bank, the same
building blocks make your complaint hard to ignore. Keep it factual, keep it
short, and keep a copy.

  • Who you are and the reference – your name, address,
    and any account, order or policy number so the business can find your case
    straight away.
  • What went wrong and when – a brief, dated account of
    the problem: what you bought or were promised, when, and how it fell short.
  • The right you rely on – name the relevant law or term
    where you can, such as the Consumer Rights Act 2015 for faulty goods or poor
    service.
  • What you want, and by when – be specific: a refund,
    repair, replacement, or a sum in compensation, with a reasonable deadline
    (14 days is common).
  • What you will do next – say politely that if you do
    not hear back you will escalate, for example to an ombudsman or the small
    claims court.

Send it by email or post, keep proof of sending, and never send original
receipts or documents – copies only.

Faulty or misdescribed goods

Under the Consumer Rights Act 2015, anything you buy from a trader must be of
satisfactory quality, fit for purpose and as described. If it is not, the law
gives you a tiered set of remedies, and your letter should make clear which
one you are exercising.

  • The 30-day right to reject – for the first 30 days
    after you take ownership, you can reject faulty goods and ask for a full
    refund.
  • Repair or replacement – after 30 days you can ask for
    a repair or replacement; the trader must do this within a reasonable time
    and without significant inconvenience to you.
  • Price reduction or final rejection – if a repair or
    replacement fails, or cannot be done, you can claim a reduction in price or
    reject the goods for a refund (which may be reduced to reflect use after the
    first six months).

If a fault appears within the first six months, the law presumes it was there
when you bought the item, so the trader – not you – has to prove
otherwise.

Poor service and work done badly

The same Act covers services, from a haircut to building work. A service must
be carried out with reasonable care and skill, for a reasonable price where
none was agreed, and within a reasonable time. If it is not, you can ask the
trader to redo the work or put it right, or to reduce the price if that is not
practical. Set out clearly what was agreed, how the work fell short, and what
you now want done. For problems with builders and home projects, see our
guidance on
home improvement claims.

Asking for a final response or deadlock letter

Many regulated businesses – banks, insurers, energy and phone providers
– have a formal complaints process, and their answer opens the door to a
free, independent ombudsman. If you are not satisfied, ask in writing for a
‘final response’ (sometimes called a ‘deadlock’
letter). Firms generally have up to eight weeks to give this. Once you have it
– or once eight weeks have passed with no resolution – you can
usually refer the matter to the relevant ombudsman, such as the Financial
Ombudsman Service. Be aware there are time limits for referring a complaint
on, so do not sit on a final response.

Claiming from your card provider (Section 75)

If you paid for goods or services costing more than £100 and up to
£30,000 on a credit card, Section 75 of the Consumer Credit Act 1974
makes your card provider equally responsible if the seller breaches the
contract or misrepresents what you bought – useful if the trader has
gone bust or refuses to help. Write to the card provider’s disputes team
explaining what you bought, what went wrong, and that you are making a Section
75 claim, enclosing copies of your evidence. If they turn you down, you can
take the complaint to the Financial Ombudsman Service.

Copy-and-paste letter templates

Use these as a starting point. Replace anything in [square brackets] with your
own details, keep a dated copy, and send by email or post with proof of
sending.

1. Complaint letter: faulty goods, 30-day right to reject

Dear [company name],

Re: [order/reference number] – faulty [product]

On [date] I bought a [product] from you for [£amount]. The item is
faulty: [briefly describe the fault]. This means it is not of satisfactory
quality, so it does not meet the standard required by the Consumer Rights
Act 2015.

As it is less than 30 days since I bought the item, I am exercising my
short-term right to reject it and I am requesting a
full refund of [£amount]. Please confirm within 14
days how you will refund me and arrange collection of the item at your cost.

Yours faithfully,
[your name] — [your address] — [date]

2. Rejection letter: after a failed repair or replacement

Dear [company name],

Re: [order/reference number]

On [date] you [repaired/replaced] my [product] after I reported a fault. The
[same/a related] fault has occurred again: [describe]. Under the Consumer
Rights Act 2015, because a repair or replacement has failed, I am entitled
to reject the goods for a refund or to claim a price reduction.

I am now
rejecting the goods and requesting a refund of [£amount]. Please confirm within 14 days. If I do not hear from you, I will escalate
this to [the relevant ombudsman / the small claims court].

Yours faithfully,
[your name] — [date]

3. Complaint letter: poor service or work done badly

Dear [company/trader name],

Re: [job/reference] carried out on [date]

You agreed to [describe the service/work] for [£amount]. The work
falls short because [describe the problem]. Under the Consumer Rights Act
2015 a service must be carried out with reasonable care and skill.

I ask you to [redo the work / put the defects right] by [date], at no
further cost to me. If that is not done, I will seek a price reduction and,
if necessary, pursue the matter through [an ombudsman / the small claims
court].

Yours faithfully,
[your name] — [date]

4. Escalation letter: requesting a final response before the ombudsman

Dear [company name],

Re: complaint reference [number]

I complained to you on [date] about [summarise]. I am not satisfied with
your response [or: I have had no response]. Please treat this as a formal
request for your final response (deadlock letter) so that I
can refer my complaint to [the Financial Ombudsman Service / the relevant
ombudsman].

If I do not receive a satisfactory final response within eight weeks of my
original complaint, I will refer the matter to the ombudsman, as I am
entitled to do.

Yours faithfully,
[your name] — [date]

5. Letter before claim: final warning before court

Dear [company name],

Re: letter before claim – [reference]

Despite my previous correspondence dated [dates], you have not [refunded me
/ resolved my complaint]. This is my formal letter before claim.

Unless you [pay me £amount / resolve this] within
14 days of the date of this letter, I intend to issue a
claim against you in the County Court to recover the sum owed, together with
interest and court costs, without further notice.

I would prefer to resolve this without court action and look forward to your
reply.

Yours faithfully,
[your name] — [address] — [date]

For the court route after a letter before claim, see our
small claims court guide; to
escalate to a free ombudsman, see
which ombudsman covers your complaint.

Sending a calm, well-evidenced letter resolves most disputes without going
further. If it does not, our
legal and claims section explains your next
steps, and if your issue concerns your rented home you can read about
housing disrepair instead.