Complaint Letter Format- Learn How to Write a Complaint Letter

Home » Complaint Letter Format- Learn How to Write a Complaint Letter

Would you like to raise a complaint against a faulty product or unsatisfactory service? If yes, then instead of an informal text message, go for a formal complaint letter to get what you want. But do you know how to write a complaint letter? In case, you have no idea, without any hesitation, check this blog post. Here, we have shared a standard complaint letter format and some sample complaint letters. Also, for your better understanding, we have explained in detail the important tips for writing an effective complaint letter.

What is a Complaint Letter?


A Complaint Letter is a formal letter written to the concerned authorities seeking a proper solution for the unsatisfied services or products you have received from them.

Writing a complaint letter is similar to a formal business letter. Compulsorily, everyone must be aware of how to write a complaint letter because having prior knowledge would be helpful in many unsatisfied instances in our daily lives, and it would also be easy to raise complaints in an effective way.

What is the Need for a Complaint Letter?

Not everyone will gain 100% satisfaction from the products or services we receive. At times, some unexpected issues might arise from the provider’s end. In such cases, positive action must be taken to resolve the issue. So, in those instances, raising a complaint would be the only way to take our issue to the provider and find a solution.

Nowadays in the recent online world, many products and service providers extend their support to customers by solving the customer’s complaints, queries, or issues 24 X 7 through a toll-free help desk and online chat support. But is that the only way to raise a complaint and get it fixed? No, not at all! The conventional method of writing a letter and a complaint email still exists.

For example, to deal with the unsatisfactory public service offered by the Government, a formal complaint letter is mandatory. Similarly, for raising grievances, resentment, wrongdoing, offense, etc. there is a need for complaint letters. Also, in many situations, if a customer support call doesn’t resolve your issue, then a complaint letter would be the ideal choice.

Complaint Letter Writing Tips

Before your start writing your formal letter, make sure to keep the below-mentioned complaint letter writing tips in mind.

Draft the complaint clearly and concisely

Always have a proper idea about your concern and then raise a complaint using clear statements in a concise manner. When writing the complaint statements, make sure to explain the inconvenience or the troubles you have faced from the products or services you have received.

The reasons for raising a complaint would be many. So, depending upon your issue, provide valid details. The complaint letter format should not be incomplete or informal. The draft should clearly express your concerns effectively with proper proof and should help or induce the provider to fix the issue.

For example, if you face any drainage issues in your street, your letter should hold the proper location details. Similarly, if you need a fix for your damaged mobile purchased in an online store, then in such cases, your complaint letter should contain the purchase details, product information, and store information.

Avoid using insulting or sarcastic comments

When writing a complaint letter, be calm. Don’t pour harsh words in the letter out of frustration. A complaint letter is a formal record, and hence it should be written in a professional tone only.

Remember, the customer support team is not responsible for the issue you face. So, try not to vent your anger to them through threatening, insulting, or sarcastic comments. You will get a proper solution for your issue only if you write the complaint letter in a cordial way.

Attach the copies of relevant documents as proof

To make the investigation process easier or to easily resolve your issue, along with the complaint letter attach the relevant documents as proof. Always try to provide valid supporting documents, depending on the issue you face.

For example, if you have received a damaged product from an online store, in that instance you can submit a copy of receipts, warranty card, guarantee card, the image of the damaged product, etc. as supporting documents along with the complaint letter. Also, in case of transaction failure, you can submit your contact information and banking details.

Complaint Letter


A Standard Complaint Letter Format

Writing a complaint letter is not a tiring task. If you are clear with the structure and the format of the complaint letter, then you can easily craft an effective complaint letter on your own. Use block format for writing a complaint letter, i.e., the entire content of the letter including the sender’s address and closing part should be left justified.

When writing a complaint letter, include the following components.

Sender’s Address

Begin the complaint letter with the sender’s address. If you are raising a complaint, then give your address with your city and zip code. It is not necessary to include your name while mentioning the sender’s address. You can include your name at the closing block of the letter.


Leave one line space after the sender’s address and mention the date you are writing the complaint letter. Writing the date as “24 August 2021” or “August 24, 2021” is a preferred format.

Recipient’s Address

Next to the date, skip a line and enter the customer care or recipient’s address. If you are unsure of the customer care contact details, check the official website of the product or service. While writing the receiver address, mention the complete address with city and zip code.

Subject line

Below the receiver’s information, mention the purpose of the letter in a crispy manner as a subject line. Writing a subject line in the complaint letter will help the concerned authorities to identify the issue easily.


After writing the subject, address the recipient using proper greeting or salutation words such as “Dear, Hi, or Hello” followed by their name and a comma. If you are writing to a public service department of a government, you can include “Respected Sir/Madam”.


Below the salutations, in the body, you can explain the purpose of the letter in a maximum of 2 to 3 paragraphs. Never deviate from your topic of complaint.

Do not exaggerate, keep it simple, and include all the necessary details related to your complaint.

In the first paragraph introduce yourself and then mention the purpose of the letter in a polite and clear way. In the second paragraph, give a detailed description of the issues or troubles you face. In the third paragraph, conclude the complaint letter by stating the resolution for your problem and thank the concerned authority for spending their time on your letter.


Close the letter with words such as Sincerely, Regards, Faithfully, etc., and include a signature block with your name and contact information.


If you attach any supporting documents along with the complaint letter, then after the signature block, leave a few lines, type “Enclosures:” and mention the list of documents you enclose, but it is optional.

Complaint Letter Template

Here is a standard complaint letter template you can follow while writing one.

Sender’s address


Zip Code




Receiver’s Name or Title

Company Name

Company Address




Salutations (Dear/Respected/ Mr. / Ms. /),


The purpose of the letter



Yours faithfully/ sincerely,


Sender’s Name

Contact Information





Complaint Letter Samples

For your better understanding, here we have added some complaint letter samples. Without skipping, refer to all those complaint letter examples and get a clear idea of how to write an error-free complaint letter as per the standard template.

Sample #1:

This is a sample complaint letter to the Customer Service Manager of a Music Instrument Store about a defect in the piano purchased from the store.


B20, Ganga Apartments

B Block, Second Floor,

Coimbatore 641001

21 August 2021


Customer Service Manager

SaReGaMa Music Instrument Store


Coimbatore 642106


Subject: Filing complaint about a defect in the Piano Purchase No MA-062/08/2021


Dear Sir,

I am writing this letter to complain to you about the defect in the Piano with respect to order no MA-062/08/2021 purchased from your store on 8 August 2021.

The piano worked properly for one week, but in the past few days, some keys have not been functioning properly. The music is very low, especially when I press the white keys. Since the Piano is under the warranty period of 5 years, I would like to get it replaced at the earliest.

I request you to resolve this issue without any delay and provide me with a new piano from the same brand. For your reference, herewith this letter I have enclosed a copy of the purchase bill and the payment receipt. I am waiting for an early response from your end.

Thank you!






Sample #2:

This is a sample letter complaining about the poor internet connectivity.


85, Bank Colony

Vishveshvaraya Street

Bangalore 560001


23 August 2021


The Customer Service Manager

FlexNet Private Limited

Bangalore 560004


Subject: Complaint about the poor internet connectivity


Dear Sir,

I am writing this letter to complain to you about the poor internet service provided by your company. The network speed is very slow, and there has been no access to the fiber internet connection for the past 2 days.

Since my work is completely based on the internet, I have a lot of pending tasks piled up because of the network issue. I have raised a complaint to your customer service team multiple times over a call, but still, I have not found a solution for this issue.

I hereby request to resolve my network connectivity issue as early as possible, or else I will quit your service with an unsatisfactory note. Also, with due respect, I would like to inform you that I will not be paying the internet service charge until this issue is resolved.

I am expecting a quick resolution from your side. Thanks in advance.



Lee James


Similar to the samples shared above, compose a neat complaint letter. Note that, you will get a quick fix for your issue only if you submit a well-crafted complaint letter.  So, while writing a complaint letter, be courteous and add all the relevant details suitable for the concerned authorities to resolve the troubles as early as possible.

Since it is a formal letter, stick to the professional tone and write the letter in a proper format. To grab the attention of the reader, you can highlight important points in the letter. Most importantly, before submitting the complaint letter, check it for spelling mistakes and grammatical errors.


We hope you are now clear about how to write a complaint letter. Basically, writing a complaint letter is not a big deal.  Just by following the tips and ideas mentioned in this writing guide, you can prepare an effective complaint letter all by yourself. As per your requirements, the experts in our team will assist you in crafting flawless complaint letters. contact us right away.

Jacob Smith Education Reading Time: 10 minutes

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