7 Capitalization Rules for Professional Business Writing

Mary Cullen
Post by Mary Cullen
Originally published October 18, 2020, updated March 16, 2024
7 Capitalization Rules for Professional Business Writing

In business English writing, it's important to capitalize words correctly for professionalism

But when should you use capitalization? After all, there are exceptions with capital letters. Here are seven English capitalization rules to follow as you create professional business emails, reports, and more.  

Here are Seven Rules for Capitalization to Implement Today


1. Capitalize the First Word of a Sentence

Use a capital letter at the start of every sentence. This rule might seem intuitive, but sometimes business writing such as for business emails can become sloppy.

For example: you might say "i need that report by Friday. it's important." These sentences improperly use lowercase letters at the beginning of each sentence. 

2. Capitalize Proper Nouns

A proper noun is a specific person, place, or thing.

Here are some examples:

  • Nelson Mandela (person)
  • The Louvre (place)
  • Microsoft (thing)

Notice how these are all names of specific people, places, or things, and not generic people (doctor), places (playground), or things (computer).

Here is a more detailed list of nouns you should capitalize:

  • Titles of books
  • Governmental bodies
  • Religions and the names of their deities
  • Planets
  • Cities, states, and countries 
  • Roads/street names
  • Names of monuments (man-made or not)
  • Planets
  • Names of companies, institutions, and brands
  • Names of departments
  • Political parties
  • Names of colleges (e.g., Auburn University)
  • Academic degrees
  • Races, ethnicities, and nationalities aside from black and white

Tip: Terms like "Mom" and "Dad" are only capitalized if you're using them as forms of address.

3. Capitalize Time Periods and Events

Capitalize time periods, historical events, and eras as you would other proper nouns. Here are several examples: 

  • Middle Ages
  • World War II
  • The Cold War
  • The Byzantine Empire
  • Boston Tea Party

*Don't capitalize centuries and century numbers (e.g., sixteenth century).

4. Capitalize Job Titles

This is where some of the confusion stems from. Job titles seem specific and general at the same time (you can be a doctor or Dr. Smith, right?). In general, job titles that come BEFORE a name are capitalized, while those that come AFTER a name are not.

For example:

  • President Jimmy Carter
  • Marlene Kim, president
  • Professor Kathryn Archard
  • Kathryn Archard, professor

5. Capitalize Days, Months, and Holidays

Names of days, months, and holidays count as proper nouns, so make sure to capitalize. Here are examples:

  • Days: Monday, Wednesday, Friday
  • Months: January, February, March
  • Holidays: Christmas, Hanukkah, Valentine's Day

Tip: Don't capitalize the names of seasons (e.g., fall) as they are not proper nouns. 

6. Capitalize After a Colon...Sometimes

Most of the time, you won't capitalize after a colon. For example, "I want one thing this morning: coffee."

However, there are exceptions to this rule. Capitalize when

  • a proper noun comes after the colon, or
  • when the words following the colon form a complete sentence.

For example, "I'm going to my favorite place on earth: Rome."

Or "Zach is moving to the new location for two reasons: He received a promotion. He also wanted to be closer to the college."

7. Capitalize the First Word of a Quote

Capitalize the first word of a quote when the quote in quotation marks is a complete sentence. Don't capitalize the first word of partial quotes:

  • Erin said, "I can't wait for my wedding!"
  • Joshua mentioned that his work was "rewarding, but exhausting."

When to Break the Capitalization Rules

Like almost everything related to English grammar, the rules can sometimes be broken. Sometimes you will have a boss or a supervisor who always wants his or her title capitalized. Sometimes, not capitalizing something looks like sloppy formatting (in a brochure, table, or program, for example). In both of these circumstances, capitalize!

When NOT to Break the Rules

You can’t break the above rules whenever you want, though. When you capitalize something “randomly,” for example, to add emphasis on social media or within an email, you confuse your readers because they assume it is a proper noun.

I was interviewed by CNN about President Trump's tendency to capitalize phrases in his tweets that normally would not be capitalized. 


Capitalization signals a brand, product, or specific person, so when it is used for other words, you create an unnecessary and unwarranted sense of importance.

What About Other Parts of Speech?

Nouns, and specifically proper nouns, are the only words you should capitalize aside from the first word in a sentence. Do not capitalize verbs or adjectives.

Learn More About Correct, Effective Business Writing

We recommend leveling up your writing skills even more by taking an online business writing course. Learn more about our Business Writing Techniques for Non-Native English Writers Course with online lessons, instructor feedback, and more. 
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Mary Cullen
Post by Mary Cullen
Originally published October 18, 2020, updated March 16, 2024
Mary founded Instructional Solutions in 1998, and is an internationally recognized business writing trainer and executive writing coach with two decades of experience helping thousands of individuals and businesses master the strategic skill of business writing. She excels at designing customized business writing training programs to maximize productivity, advance business objectives, and convey complex information. She holds a B.A. in English from the University of Rhode Island, an M.A. in English Literature from Boston College, and a C.A.G.S. in Composition and Rhetoric from the University of New Hampshire.