Most of the times a Formal letter forms a part of the IELTS Written Exam. A formal letter could be written to a business colleague or someone you don’t know. Here are some points that need to be kept in mind in order to write a formal Letter.
1. Step 1: Begin the letter with Greetings like ‘ Dear Madam’ or ‘Dear Sir’
2.Step 2:Divide your letter into clearly defined purposeful paragraphs.
a)Paragraph 1: Purpose for writing.
b)Paragraph 2:Explain the problem.
c)Paragraph 3:What you would like them to do?
d)Close your conversation with polite remarks.

There are some salient features of Formal Writing:
a) Purpose of the letter should be written instantly.
b)The letter should be written in Passive voice.
c)Formal Linking words such as Moreover and Furthermore should be used.
d)Incorporate more Nouns than Verbs.
e)Sign up Formally along with writer’s full name.