Business letters are one of the ways of written communication. There are different kinds of business letters depending upon the nature of work. Business memo are used for the internal communication of the organization while business letters are used for the external communication i.e. with other organizations. Business letters are formal letter so not any specific format is required.

If you are going to write the business letter then I must give you some tips for the writing pattern.
Write your name, address, postal code and phone number at the start.
Purpose of the letter should be mention clearly and mention date of submission also.
You must address the person in a professional and positive way like Madam/ Dear Sir.
7C’s of business communication should also consider. At the end mention your name and ending should be strong. Proofread your letter atleast one or two times. All spelling should be correct and punctuation must be placed on proper places.
Type your letter in a very professional way and get hard copy and do your handwritten signature

If you are looking for the business letter then this site provide you professional sample business letter. You can also download it. This site gives you lots of information and knowledge about business letter.