This is an IELTS formal letter example.
It is formal as it is to an insurance company, and is not to someone that you know. It is an example of how to write a letter of complaint.
See comments on the letter at the bottom of the page.
Dear Sir / Madam,
I am writing to you as I recently received a letter from you informing me that the insurance premium for my car is going to increase from next month.
As you will be aware if you check my records, I have held my insurance with your company for nearly seven years now. During this time, I have never had an accident and never had any reason to make a claim on my insurance.
I understand that at times prices need to be increased. However, this increase you are suggesting will result in a 20% increase in the amount I pay each month, a rate I feel is too much.
I would therefore like you to write back to me and explain why such an increase has been proposed. If you are unable to justify it to my satisfaction, then I am afraid that I will have no other option but to move my insurance to another company.
I look forward to hearing from you,
Mr Mahmoud Khan
The answer clearly addresses all the bullet points from the question. The writer gives reasons why the letter is being written and why the increase is considered unfair, and then goes on to explain what he wants the company to do to resolve the situation.
The writer expands on his ideas by giving extra details. For example, he explains that he has had insurance for seven years and never had an accident, and he also explains how the increase will affect him i.e. result in a 20% rise in his payments. It is important when writing a letter to give extra information to support the letter whilst remaining on topic.
The tone of the IELTS formal letter is well-controlled, with appropriate opening (Dear Sir / Madam) and closing (Yours faithfully) phrases, and further phrases that ensure the formal letter still remains polite (I understand that..., I’m afraid..., I look forward to hearing from you...) despite the fact that it is a letter of complaint.
There are some other good examples of phrases appropriate to a semi-formal or formal letter (As you will be aware..., I would therefore like you to...).