You're staring at a complaint letter prompt with 20 minutes on the clock. You need something that sounds professional, persuasive, and properly structured. Here's the thing: most students aiming for Band 7 actually land in Band 6 because they don't understand what examiners actually want in a formal complaint letter.
A complaint letter isn't a place to vent. It's a negotiation. You state the problem, explain why it matters, and request specific action. Skip any of those elements, and you'll lose points on Task Response alone. That gap between Band 6 and Band 7 comes down to hitting all three.
In this guide, I'll show you exactly what Band 7 looks like, how to structure it so examiners can't miss your point, and where most students stumble. By the end, you'll know how to write a complaint letter that scores at the Band 7 level.
Band 7 isn't about using fancy words or complicated sentences. It's precision, tone control, and delivering exactly what the prompt asks for—nothing more, nothing less.
The IELTS band descriptors say a Band 7 response shows "good accuracy" and "uses a range of structures with some flexibility." For complaint letters specifically, that means you can "select, organize and present relevant information" while keeping an "appropriate tone."
What does that actually look like?
Band 7 hallmark: The reader understands the entire complaint after the first paragraph. Everything after that adds evidence and credibility.
No rambling. Band 7 complaint letters follow this exact format:
This structure is non-negotiable. It shows you understand formal business communication and makes your argument impossible to ignore.
Let's compare how Band 6 and Band 7 writers handle the same scenario.
Scenario: You ordered a laptop online and it arrived damaged.
Weak (Band 5-6): "I bought a laptop last week and it came broken. This is very bad and I am upset. I need a new one or my money back. Please help me."
What's missing? No date. No order number. No description of the damage. No explanation of why it matters. The tone is casual, almost conversational. An examiner would mark this as "partially met" for Task Response, not fully met.
Strong (Band 7): "I am writing to formally lodge a complaint regarding a laptop (Model XPS 13, Order #789456) that I purchased on 12 April 2026. Upon delivery on 15 April, I discovered the device had sustained significant screen damage and was non-functional. As I required this laptop for my university coursework due the following week, the faulty product caused considerable inconvenience and delay. I kindly request either a full refund or a replacement unit to be sent within seven days."
Notice the difference: specific date, order number, clear description of damage, explained impact, concrete request with a deadline. The tone is formal and measured throughout. An examiner scores this as a complete Task Response.
Your word choices tell the examiner whether you control formal register. Band 7 writers avoid casual language and choose precise, appropriate alternatives.
Weak: "The staff were not nice and didn't help me at all."
Strong: "The staff displayed a lack of professionalism and failed to provide adequate assistance."
Here's the formal vocabulary that marks Band 7 complaint letters:
Tip: Use one formal phrase per sentence max. Overusing sophisticated language reads as fake and awkward. Balance formal structures with clear, direct communication.
You're close to Band 7, but these errors will knock you back.
1. Vague or missing details. "The hotel was dirty" lands you in Band 6. "The bathroom fixtures were visibly corroded and the mattress retained moisture" gets you to Band 7. Specificity proves you actually experienced the problem.
2. Emotional language instead of measured complaint. "I'm furious and disgusted" signals poor register control. "I must express my strong dissatisfaction" maintains professionalism.
3. No clear request for action. If you don't say what you want, you've failed Task Response. Always include: "I request that you..." or "I expect the company to..."
4. Rambling without structure. Band 7 letters run 160-180 words. You're aiming for precision, not volume. Every sentence must support your complaint or request.
5. Mixing formal and informal tone. "I am extremely upset and need you guys to sort this ASAP" signals a Band 5-6 writer. Choose formal and stick with it.
Weak: "I went to your restaurant and the food was horrible and made me sick!!! I want a full refund immediately or I'll tell everyone how bad you are."
Strong: "I dined at your establishment on 20 April and consumed a chicken dish that appeared undercooked. I subsequently suffered acute food poisoning requiring medical attention. I request full reimbursement of the meal cost (GBP 28.50) plus compensation for medical expenses incurred."
Before you submit, run through this checklist. It mirrors how IELTS examiners actually evaluate complaint letters.
Task Response (25% of your score): Does your letter address all parts of the prompt? Have you stated the problem, explained why it's serious, and requested action? Read the prompt again. If you've missed anything, rewrite before you move on.
Coherence and Cohesion (25%): Can someone read straight through without confusion? Check that your paragraphs follow a logical order. Use linking phrases like "As a result," "In addition," or "Consequently" to show how ideas connect. When you're working on strengthening these connections, our guide on eliminating circular arguments shows how to keep your logic flowing smoothly.
Lexical Resource (25%): Are you using formal vocabulary consistently? Highlight every basic word (good, bad, very, really, nice) and replace it with something more sophisticated. Band 7 does not require rare words, just appropriate ones.
Grammatical Range and Accuracy (25%): Count your sentences. Can you write at least one complex sentence per paragraph using subordinate clauses (with "although," "because," "if")? Check spelling and verb tense agreement. One error rarely drops you a band, but three or four errors signal Band 6.
Tip: Read your letter aloud. If you stumble, your examiner will too. Awkward sentences usually mean grammar issues or word choice problems.
Here's a complete complaint letter that hits all Band 7 criteria:
Prompt: You ordered an expensive coat online and it arrived in the wrong color with a torn seam. Write a letter to the company.
Dear Sir or Madam,
I am writing to lodge a formal complaint regarding a winter coat (Style WC-2847, Color: Navy) that I ordered from your website on 8 March 2026 under Order #556234.
Upon delivery on 15 March, I discovered two significant defects. First, the coat arrived in charcoal gray rather than the navy blue I had selected. Second, the left seam along the shoulder contains a visible tear approximately 3 centimeters in length. Given that this item cost GBP 89.99, these quality issues are entirely unacceptable.
The faulty product has proven highly inconvenient, as I required the coat for business travel scheduled to commence on 18 March. I have consequently incurred additional expenses purchasing a replacement elsewhere.
I request that you send a replacement coat in the correct color and undamaged condition within five business days, or alternatively, process a full refund including return shipping costs. I trust this matter will be resolved to your earliest convenience.
I look forward to your prompt response.
Yours faithfully,
[Your name]
Why this works: The complaint is explicit from the opening. Details are specific: order number, dates, measurements, price, exact defects. The impact is clear: missed travel, additional expense. The request is concrete and time-bound. Tone remains formal throughout. Word count is 165 words, right in range. Sentence variety shows grammatical range. This letter demonstrates all four scoring criteria at Band 7 level.
The fastest way to diagnose where you're losing points is to use an IELTS writing checker designed specifically for this task type. When you get feedback on your complaint letter, look for responses to these specific questions:
Most students think they need to rewrite everything. Usually you just need to tighten three or four sentences and swap casual words for formal ones. A checker that gives line-by-line feedback shows you exactly where those changes should go. Once you understand what Band 7 sounds like in a complaint letter, similar principles apply to other Task 1 formats. For example, our band score guides cover the specific criteria for each letter type, so you can apply the same discipline across all formal writing tasks.
Getting feedback is one thing. Acting on it is another. When you receive IELTS writing correction feedback, prioritize changes in this order:
First: Check Task Response. Did you miss any part of the prompt? Add or restructure content if needed.
Second: Tighten your tone. Replace informal words with formal alternatives. Remove any emotional language.
Third: Add specific details. Generic complaints never reach Band 7. Insert dates, numbers, product names, exact amounts.
Fourth: Vary your sentence structures. Write at least one sentence using "although," "because," or "if" per paragraph.
After you make these corrections, run your letter through the checker again. Most students see a 0.5 to 1.5 band jump once they apply focused feedback.
Get instant band score feedback on your formal complaint letter. See exactly where you are strong and where you need to tighten your formal tone and task response.
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