How to write professional business email subject lines

20 Jan 2023

Email continues to be the most widely used form of business communication, and with so many messages vying for attention you need to make yours stand out. The quickest, and easiest way to make your email stand out in a crowded inbox is with the subject line. That’s why it’s critical to know how to write email subject lines.

People choose which email to open and read based on two things. One of them is the subject line. That’s why email subject lines are important.

Most of us have inboxes full of emails and every time we look at our inbox, we must choose which message to open first. Most people choose which message to open based on two things:

  1. Who sent the email; and/or
  2. The subject line.

For the first item, the name of the sender, we don’t control how that influences the recipient. They may see our name and open the email, or see our name and be inclined to avoid our message. You never know.

Luckily, our name isn’t the only thing that influences which email people open first. The subject line plays a big part in the decision, that is something we can control. And that is why email subject lines are important.

Subject lines tell people what a message is about and why they should open it

Knowing the subject line is important is not the same as knowing how to write email subject lines so it will be eye-catching and quickly seen as important by the recipient.

So, what should you write? When it comes to writing an attention-grabbing, informative subject line, what are the right things to include?

The two things that must be in that subject line are the topic and purpose of your communication.

In addition, you may highlight the urgency, confidentiality, or other important characteristics of the message if needed.


If you’re sending the first email to someone as opposed to writing a reply, your email is the start of a conversation, so the first thing you should do is let them know what that conversation is about. This is the topic, and it must be clear. If I can’t tell what the topic of an email is, I’m not going to know how to prioritize reading it against other things I’ve been sent.

What are examples of topics you might use in the subject line? Within a couple of words, you can name the piece of work, the project or the program, or the situation that you want to write about. If you want to write about next month’s budget reports, the subject line should include the words ‘Next month’s budget report’ to make it instantly obvious to the recipient what the email is about.

Whatever your topic is, include it as a short statement when you write the email subject lines. It only takes a couple of words to make clear what the topic is. Being too wordy here can have the opposite effect.


When you send an email, it’s because you want the recipient to do something with the information. The topic by itself isn’t enough, it doesn’t tell the recipient what they need to do with the email. Do they need to read and reply to it now, or is the information not needed until next month?

If the receipt doesn’t know what they’re meant to do with a message, they can’t assess how important it is or how time-sensitive it is to prioritize properly. The purpose is what you want the recipient to do with the information you’re sending them. Are you asking for help? Need a decision? Giving them an instruction? Are you answering a question they want to know the answer to? Giving someone a heads up about something? The list goes on, but you get the point.

Combining the topic and purpose in the subject line creates a clear statement of what the email is about. Whoever receives your email will understand it and can evaluate whether they should open and read the message, and you’ve effectively reduced the chances that your message won’t be opened/read or prioritized appropriately.

The formula for a great subject line

To recap the important points we’ve covered so far:

An email’s subject line influences the chances of it being opened and getting the attention it needs. We can’t control the order in which people read their emails, but a good subject line can increase the chances that our messages will be opened and not ignored.

Two formulas for clear subject lines:

  • Single-topic emails = [URGENCY] + [TOPIC] + [PURPOSE]
  • Multi-topic emails = [URGENCY] + [THEME] + [TOPIC & PURPOSE SUMMARY]

Email subject lines that use these structures give the recipient all they need to make an informed choice about when to open the message.

In addition to using the formula, make sure to only use urgency labels when absolutely necessary and don’t write clickbait or bait and switch subject lines.

Examples of how to write email subject lines for business emails

Here are a few more examples of less-than-ideal subject lines along with better versions using the methods described in this section:

Bad subject line Better version Format of better versions
Here you go April sales numbers – please update the reports TOPIC + PURPOSE
URGENT!!! [URGENT] Check if this announcement impacts Projects Apex & Everest URGENCY + PURPOSE + TOPICS
FW: FW: FW: RE: FW: FW: Derek Derek is leaving – Please share gift ideas TOPIC + PURPOSE
Status update Project Apex – status is yellow – need help with three items THEME + (TOPIC & PURPOSE SUMMARY)
FYI Please review and identify if this impacts you PURPOSE + TOPIC
New priorities? Re. CEO priorities statement – does it impact us? TOPIC + PURPOSE
FW: FW: FW: FW: Re: FYI – 3G587P92 Please update case file #3G587P92 today URGENCY+ PURPOSE + TOPIC

In these examples, you can see the topic and purpose can switch places. This sometimes happens from a combination of the way we structure sentences and our personal styles. Generally, it is better to have the topic before the purpose, but they can switch places if the subject line is short enough.

And finally, when you write an email subject line, never send an email with a blank subject line. This may seem obvious, but it happens more than you think. A blank subject line is a great way to ensure people will ignore your message while providing them with the excuse that they didn’t see it.

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