Formal Complaint Letter Templates and Examples

Five sections, four complaints

Every formal complaint follows the same five sections. Choose a complaint type to see a complete letter; the band of colour beside each paragraph marks its section.

The issueFacts and datesThe impactThe remedyDeadline and next step

Complaints Department, Northline Energy, PO Box 410, Leeds LS1 4AB Re: Account 77120458, incorrect bill dated 2 May 2026 Dear Sir or Madam,

I am writing to complain about my electricity bill dated 2 May 2026, which charges me £486.20 for April.The bill is based on an estimated reading of 14,220 units. My actual meter reading on 1 May was 12,960 units; a dated photo is enclosed. I reported this by phone on 8 May (reference CR-55102), but the bill has not been corrected.The overcharge of about £250 has left my account in arrears, and I have received a late-payment warning.Please issue a corrected bill based on my actual reading and remove the late-payment warning from my account.I would be grateful for your response within 14 days. If the matter is not resolved, I will refer it to the Energy Ombudsman.

Yours faithfully,
Lena Novak Enclosed: my meter photo (1 May), the bill (2 May), my notes of the call (8 May)

Account number in the subject lineThe letter reaches the right file immediately.Exact figures and unitsThe company can check every number against its records.Name the next step calmlyMentioning the ombudsman shows you know the process.

How to write a formal complaint letter that gets results →

The evidence to enclose

Send copies, never originals, and list each one at the end of the letter under “Enclosed”.

Receipts and order confirmations Prove what you bought, when and for how much.

Bills and statements Highlight the incorrect lines.

Dated photos Damage, faults, readings, room conditions.

Previous messages Emails, texts and chat transcripts.

Call notes Date, time, name of the person and any reference number.

Expert reports An engineer’s or surveyor’s written finding.

Contracts and terms The clause the company has not met.

Costs you incurred Receipts for taxis, repairs or replacements.

Authoritative phrases

Firm language is polite and precise. These phrases show you know your position and expect an answer.

Purpose	Phrase
Opening	“I am writing to make a formal complaint about…”
Stating facts	“On 8 May I reported the fault by phone (reference CR-55102).”
Showing the gap	“Your terms state that…; however, …”
Requesting a remedy	“To resolve this, I am requesting…”
Setting a deadline	“I would be grateful for your response within 14 days of the date of this letter.”
Naming the next step	“If I do not receive a satisfactory response, I will refer the matter to…”

Guides on complaint letters

3 guides · newest first

How to Write a Formal Complaint Letter That Gets ResultsFive-section complaint letter structure, authoritative language patterns, and four full templates for billing, product, service, and workplace complaints.Apr 23, 2026 · 16 min read

Formal Complaint Letter to Landlord - 10+ Templates10+ formal complaint letter templates for tenants covering repairs, security deposits, neighbor noise, mold, pests, illegal entry, and habitability issues.Apr 15, 2026 · 20 min read

Formal Complaint Letter Templates and FormatFormal complaint letter templates for products, services, workplace issues, insurance disputes, and more. 10 professional examples with proper format and escalation guidance.Apr 3, 2026 · 25 min read