Introduction
Letters of enquiry describe what the writer wants and why. The more unusual the request, the more convincing the reason needs to be.
Content
Subject Heading
This should inform the reader that this is an enquiry or request; e.g.
Enquiry about Textbooks
Request for Brochure
Query about Website
Question regarding Product Components
First Paragraph
This should tell the reader what you want; e.g.
Please send me... (for things that the organisation offers to send)
I would be grateful if you could tell me... (for things that are not normally offered)
I am writing to enquire whether... (to see if something is possible)
I would especially like to know... ( + a more detailed request)
Could you also... ( + an additional enquiry or request)
Second Paragraph
This paragraph tells the reader why you are contacting his or her organisation, and gives further details of the enquiry.
There are two reasons why you may contact an organisation:
you have contacted this organisation before, and want to again.
you have not contacted this organisation before, but you have heard about them. You should describe from where, such as from an advert or a recommendation; e.g.
I saw your advert in the HK Daily on Friday, 16 January 2015.
Your company was recommended to me by Ms. Elsie Wong of Far Eastern Logistics.
Final Paragraph
This paragraph should contain a polite expression and/or an expression of thanks to the reader. The degree of politeness (and therefore the length), depends on how unusual or difficult your request is. Possible language includes:
Thanks. (For a very informal and normal enquiry or request)
I look forward to hearing from you.
I am looking forward to hearing from you.
Thank you for your assistance.
Thank you very much for your kind assistance.
I appreciate that this is an unusual request, but I would be very grateful for any help you could provide. I look forward to hearing from you.
If you think the reader might have further questions, you can suggest that he or she contact you; e.g. 'If you have any questions, please do not hesitate to contact me'.