Business letters: Subject line

On this page

• When to use a subject line
• How to format the subject line
• Where to place the subject line
• Additional information

When to use a subject line

The subject line is an optional letter part. When you want to clarify the topic of the letter and give it more prominence, you can state it in a subject line.

Also, you can use a subject line for information that would otherwise go in a reference line.

How to format the subject line

To make the subject line stand out, use one of the following formats:

• bold font, with initial capitals on all major words
  OR
• all capitals

You may use the introductory word Subject, but it isn’t essential.

Where to place the subject line

Place the subject line between the salutation and the body, leaving one blank line above and below it. (See Business letters: Model letter in recommended format.)

In full block style, the subject line begins flush with the left margin.

Additional information

• Correspondence and addresses – Guidelines and resources
• Business letters: Model letter in recommended format