Commas in Work Emails: 8 Simple Rules With Real Examples

Priya Sharma

Priya Sharma writes English learning guides for ESL students. Pune-based language enthusiast.

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Quick answer: In professional emails, put a comma after the greeting ("Hi Maria,"), after the closing ("Best regards,"), after intro words like "However," and before "and," "but," or "so" when they join two full sentences. Don't put a comma between a subject and its verb, and don't join two full sentences with only a comma.↗ Share on X

To use commas correctly in a professional email, remember a few fixed places: after the greeting ("Hi Maria,"), after the sign-off ("Best regards,"), after introductory words ("However," "Unfortunately," "As discussed,"), and before "and," "but," or "so" when they join two complete sentences. Just as important: never put a comma between the subject and the verb, and never join two full sentences with only a comma. If you follow these points, most of your emails will already look clean and professional.

Below are eight rules, each with a wrong and a right example. You can use them as a checklist before you hit "Send."

Rule 1: Where does the comma go in the greeting?

READ ALSOWho, Which, That: Relative Pronouns for Everyday English →Master Adjectives & Adverbs in Professional Email Writing →That vs. Which: The Comma Test That Settles It Every Time →

Put a comma after the name in the greeting.

• Wrong: *Hi Maria*
• Wrong: *Hi Maria.*
• Right: Hi Maria,
• Right (more formal): Dear Mr. Lopez,

In very formal letters in American English, you may see a colon: *Dear Mr. Lopez:* That's correct too, but a comma is normal in email.

Technically, grammar says "Hi" needs a comma before the name too (*Hi, Maria,*). In real business email, almost nobody does this. *Hi Maria,* is perfectly professional.

Rule 2: Where does the comma go in the sign-off?

Put a comma after the closing words, then your name on the next line.

• Right:

Best regards,

Daniel

• Wrong: *Best regards Daniel*
• Wrong: *Best regards.*

Common sign-offs: *Best,* *Kind regards,* *Thank you,* *Thanks,* *Sincerely,* (very formal).

Rule 3: Comma after introductory words and phrases

READ ALSOMake or Do? The Simple Test Plus 40 Everyday Expressions →Transition Words for Work Emails That Don't Sound Stiff →English Conditionals for Talking About Your Career Plans →

When a sentence starts with a short word or phrase that "sets the stage," add a comma after it.

A small tip: if the intro is very short (two or three words), some writers skip the comma. In business email, keeping it is safer and easier to read.

Rule 4: Comma before "but" or "so" joining sentences

A full sentence (also called an independent clause) has a subject and a verb and can stand alone. When you join two of them with and, but, or, so, yet, put a comma before the joining word.

• Right: *I sent the invoice yesterday, but I haven't received a confirmation.*
• Right: *The price went up, so we need a new quote.*

But if the second part is not a full sentence, don't add the comma:

• Right: *I sent the invoice yesterday and called the client.* (No "I" before "called," so it's not a full sentence.)
• Wrong: *I sent the invoice yesterday, and called the client.*

Quick test: cover the first half. Can the second half stand alone as a sentence? If yes, use the comma.

Rule 5: Don't join two sentences with only a comma

This is one of the most common mistakes, and it has a name: the comma splice.

• Wrong: *Thanks for your email, I will check the numbers today.*

You have three easy fixes:

1. Use a period: *Thanks for your email. I will check the numbers today.*

2. Add a joining word: *Thanks for your email, and I will check the numbers today.*

3. Use a semicolon (less common in email): *Thanks for your email; I will check the numbers today.*

In email, option 1 is usually best. Short sentences are easier to read on a phone.

Rule 6: Commas in lists

Use commas to separate three or more items.

• Right: *Please bring your ID, your contract, and a pen.*
• Also right: *Please bring your ID, your contract and a pen.*

The comma before "and" is called the Oxford comma. It's optional, but it can prevent confusion:

• Confusing: *I'd like to thank my managers, Ana and Tom.* (Are Ana and Tom the managers?)
• Clear: *I'd like to thank my managers, Ana, and Tom.* (Three separate thanks.)

Pick one style and use it in every email. Many company style guides choose the Oxford comma for this reason.

Rule 7: Commas around extra information

If you can remove a part of the sentence and it still makes sense, that part is "extra." Put commas on both sides.

• Right: *Our manager, Laura Kim, will join the call.*
• Right: *The report, which I attached, has the final numbers.*

If the information is necessary to know *which* one you mean, don't use commas:

• Right: *The report that I sent on Monday has an error.* (Tells which report.)

A common error is using only one comma: *Our manager, Laura Kim will join the call.* Either use two commas or none.

Rule 8: No comma between subject and verb

Long subjects make people want to "breathe" with a comma. Don't.

• Wrong: *The people who attended the training last week, will get a certificate.*
• Right: *The people who attended the training last week will get a certificate.*

Same with "that":

• Wrong: *I think, that we should wait.*
• Right: *I think that we should wait.*

What are other common comma mistakes in work emails?

Note the last one. In American English, the comma separates thousands (1,500), and the period marks decimals (2.5). Many other languages do the opposite, so this is an easy mistake for non-native speakers.

What does a full email with correct commas look like?

Here is a short example that uses most of the rules above:

Hi Daniel,

>

Thank you for the quick reply. As discussed, I'm sending the updated proposal. The new price is $1,250, and delivery is still on May 12, 2026.

>

Unfortunately, the design team needs two more days for the logo. Our project lead, Priya Shah, will send it on Thursday.

>

Please review the proposal, the timeline, and the payment terms. If anything is unclear, let me know.

>

Best regards,

Ana

Read it slowly and look at each comma. Every one follows a rule from this article.

How do you check your commas in 60 seconds?

Use this quick checklist:

1. Greeting ends with a comma.

2. Sign-off ends with a comma.

3. Words like *However, Unfortunately, As discussed* have a comma after them.

4. No two full sentences are joined with only a comma.

5. Extra information has commas on both sides.

6. No comma between a long subject and its verb.

7. Numbers use commas for thousands (1,500).

Reading your email out loud also helps. A natural pause often means a comma, but not always, so trust the rules more than the pause.

Your next step

Open the last three work emails you sent. Check them against the 60-second checklist above and mark every comma you'd change. Most people find the same one or two mistakes again and again. Write your personal mistakes on a sticky note next to your screen, and check only those before you send your next ten emails. After that, the correct commas usually become automatic.

FAQ

Do I need a comma after "Hi" and before the name?

Strict grammar says yes ("Hi, Maria,"), but almost everyone in business writes "Hi Maria," with one comma after the name. Both are fine. Just be consistent.

Should I use the Oxford comma in emails?

The Oxford comma is the one before "and" in a list, like "red, white, and blue." It's optional. Many companies use it because it prevents confusion. Pick one style and use it every time.

Is it wrong to start a sentence with "And" or "But" in a work email?

No. It's acceptable in normal business writing. Just don't put a comma right after "But" at the start of a sentence unless something extra follows, like "But, as I said, we can wait."