What is Business Letter? The most important consideration for the writer of a business letter is to select a proper form for sending his message. There really is no correct or incorrect set of letter mechanics. Still, there are certain conventions and trends which govern the form and style of business letters. These conventions concern the layout, form, letter parts and general structure of a letter. They exist because, over the years, people have agreed on a set of basic rules for composing neat, complete and attractive letters.


No matter which form, style or format one resorts to, there are some essential mechanical requirements of a letter. These requirements are the standard letter parts. They are:
1. Heading
2. Date
3. Inside Address
5. Body of the Letter
6. Complimentary Close
7. Signature

1. Heading: Heading consists of the name and address of the company on whose behalf a letter is written. Most business organizations have their letterheads, printed in bold letters, with details of their title, address, telephone numbers, fax numbers, e-mail address, etc. In case of printed letterheads, in all forms of letters, the Heading is made at the head of the page, leaving equal space on both sides. In case of typed Heading, depending on the format being used, it may be mentioned to the right or left of the center, leaving suitable space below the top of the paper.
2. Date: Date is an essential part of a business letter since it serves the purpose of proof as to when the letter was written.  Date is mentioned to the right of the corner, leaving double space below the last line of Heading. It should always be written in full, on 22 July 2007 or July 22, 2007. Mentioning of Date in figures should be avoided because it may sometimes cause confusion, besides being defaced or changed. In Full-Block Form, Date to is written to the left of the center, leaving double space after the Heading.
3. Inside Address: Inside Address carries the name and complete address of the person or the company to whom the letter is addressed. The two addresses i.e. the inside address and the outside address on the envelope should always be in the same form.
Inside Address should be suitably and correctly split into three or four lines. It is always written alongside the left margin, leaving suitable space after the preceding part. In case of personal inside address, the name of the person should always be preceded by the title of Mr., Miss, Mrs., Dr., Prof., etc. If a title of the firm, to whom the letter is written, begins with a personal name, it is preceded by ‘Messrs’. The title ‘Messrs’ should always be used in full and never as ‘WS.’
4. Salutation: Salutation is a friendly, formal greeting to the reader. It is always typed at the left-hand margin, leaving suitable space after the inside address, and is followed by the mark of colon or comma. If the addressee of the letter is singular, one of the following salutations may be used:
Dear Sir, Dear Madam, My dear Sir, My dear Madam, My dear Dr. Karim, etc.
In case the addressee being a firm or an organization, one of the following salutations may be used:
Dear Sirs, Dear Mesdames, Gentlemen, etc.
5. Body of the Letter: The Body of the letter contains the message. It should be typed leaving double space after the Salutation. In case subject of the message is also written, the body should begin leaving double space after the Subject Line. The message should be suitably divided into paragraphs, observing single space between the lines and double space between the paragraphs. Normally, three to five-stroke spaces is left to begin the first line of each paragraph. However, in Block Form and Full-Block Form, all lines of a paragraph begin at the left-hand margin.
6. Complimentary Close: If Salutation is the ‘hello’ of the letter, Complimentary Close is it is good-bye.’ It should always be directly related to the salutation, both in form and spirit. It should show the same degree of formality is observed in the Salutation. It is written leaving suitable space after the last line of the message. In Full-Block Form, it is always written at the left-hand margin. Most commonly use Complimentary Close includes:
Yours truly, Very truly yours, Sincerely yours, Cordially yours, Gratefully yours, etc.
7. Signature: Signature is the most important part of a business letter. Without signature, a business letter carries no worth. It is made beneath the Complimentary Close, leaving three to four-stroke spaces. In Full-Block Form, a signature is also made at the left-hand margin. It usually bears the name and designation of the person who signs it. A signature should always be made in ink and never with pencil or rubber-stamp. As far as possible the signature one makes should be and reflective of the name of the signatory.


Some letters may ask for certain additional parts which are not the requirements of all letters. One or more of these parts may be mentioned, as and when required. These parts are:
1.          Reference Line
2.         Attention Line
3.         Subject Line
4.         Identification Line
5.         Enclosure Line
6.         Carbon Copies

1. Reference Line: Reference Line denotes the reference number of letters. Its purpose is to link a letter with previous or the subsequent correspondence to be made on a subject. Different organizations have different ways to mention the reference number but, whatever form it may take,  the purpose remains the same i.e. to enable the reader to link the letter with the previous/subsequent correspondence.  Although it is regarded as a Non-Essential part, nowadays almost all organizations mention Reference Line to make things convenient for the senders and the receivers.
2. Attention Line: Sometimes a letter is sent to a firm with the expressed desire to invite the attention of a particular individual, In that case, his name is mentioned separately and distinctly. Attention Line is usually typed in center of the page, leaving double space after the Inside Address. It is mentioned only when the Inside Address is impersonal. If Inside Address already contains a name, no Attention Line is required.
3. Subject Line: Purpose of Subject Line is to invite the attention of the reader to the central idea of the message. It is usually typed at the left-hand margin in capital or bold letters, leaving double space after the Salutation. Some organizations, however, prefer using the Subject Line after the Inside Address of the letter. Subject Line is mentioned only in long letters. In a short letter, it is not a requirement.
4. Identification Line: Identification Line comprises the initials of names of the persons who are involved in drafting and typing Of the message. The purpose of Identification is to Show who can and dictated a letter and who typed it. Initials of the person who drafts the message in capital letters whereas initials of the person who types the message made in small letters. The two initials are separated by using the colon mark.
5. Enclosure Line: Enclosure Line has mentioned as and when a letter contains enclosure. It may be a copy of some-letter, or a document; or a cheque, etc. The number of documents, so enclosed, is against the word ‘Enclosure.’ The objective is, of course, to indicate to a recipient of the letter of a document or documents with it. Enclosure Long is says made on the left hand begin, leaving double space after the part preceding it.
6. Carbon Copies; Sometimes copies of a particular letter are same of some other person or persons. If so, a record of it is kept by mentioning names and addresses of these persons. The abbreviation used for this purpose is ‘cc.’ ‘bcc’ is used to send a copy to a third person without bringing it into the knowledge of the original addressee.