Top 7 Email Subject Line Best Practices for B2B Success in 2023

What a shame.

You — and your subject matter experts — have worked so hard to write and design a helpful content offer, curate a segmented list of prospects that the content speaks to, and set up email nurturing campaigns to make it known to your target audience. Finally, you present the offer within a well-crafted email to the right contact list… and the email never gets opened.

All of your work goes down the drain because your email subject line — and your email marketing channel — failed. All you needed to do was implement email subject line best practices, and your bottom line could look so much different.

Email Subject Line Best Practices:

Get Personal
Choose Words Wisely
Be Brief
Stay Specific
Show Personality
Go Visual
Don’t Shout

We’ll share some do’s and don'ts of B2B email subject lines and explore how to get your emails opened based on current industry experts and research. After reviewing the best practices list, check out some examples of high-performing subject lines.

It’s worth noting that open rate should not be your primary performance measure for your email marketing channel. Open rates can be artificially inflated by email clients like Apple mail. In addition, click rate and other engagement metrics are much more meaningful measures of whether your email gets the person to take the desired action. Open rate is a leading indicator of email success, because they cannot take the action you want them to take without first opening the email.

Why B2B Email?

Just in case you need convincing that email remains a critical part of a complex B2B company’s inbound marketing strategy, remember that email is:

the most common form of communication in the business world
the most direct way to reach an online audience
used often, with an average person sending/receiving 121 business emails per day¹
on people’s minds, with 55% of Americans checking their work emails within an hour of waking — before ever going to work²

Yes, it’s important to regularly examine your company’s email marketing strategy — including setting up your send for optimal deliverability to make sure you get to the inbox. When you see which tactics are having the most success with your audience, you can deploy new strategies wherever necessary.

What makes someone open a work email?

So, what dictates whether your intended contact opens your email? Here are the biggest factors:

Sender’s name — If someone sees an email from a personal account (not your corporate email account), readers are more likely to feel like it’s a personal, important message sent just to them.
Your recipient list — No surprise, the right audience determines your marketing success. Segment contacts into different lists (sorted by age, gender, location, job title, last contact date, etc.) because different personas respond better to more personalized emails.
Date and time — The best times to send emails are typically during normal business hours; when people are glued to their work computers. Experiment, though, to see if different days throughout the week work best for your company.
Subject line and preview text — You only get one shot to make a first impression. Miss once, and your audience could write you off as spam without even giving you a chance. Subject lines are so important that they are the top email element to undergo A/B testing (91%), far outpacing calls-to-action (53%).3

Top 7 email subject line best practices

1. Get Personal

What we mean is to personalize subject lines, when possible. Using merge tags, you can show each recipient’s first name and/or last name, which has shown to skyrocket open rates. This technique can be combined with marketing automation to create emails that feature timely offers such as a post-purchase deal or a birthday special.

2. Choose Words Wisely

One of our top sessions at HubSpot’s annual INBOUND event is always Jay Schwedelson of Worldata. His newsletter on “what’s hot” in email marketing also never fails to open eyes, and he recently suggested using these words in subject lines to increase B2B open rates:

“2023” — 31%
“Limited” — 28%
“In-Stock” — 28%
“Do’s and Don’ts” — 22%
“Oops” “Uh oh” and “Yikes” — 21%

If your subject line can create a sense of urgency, it helps increase open rates. A promotion with a set time frame can entice action. Lastly, use phrases that make your recipient feel special: “You’re invited” or “An exclusive offer for you” can create a sense of belonging.³

3. Be Brief

Most smartphones cut off subject lines around 35 characters, so you’ll want to be punchy and concise to quickly entice potential readers. Subject lines with fewer than 20 characters have a 21% higher open rate for B2B companies (thanks again for the stat, Jay). Definitely use fewer than 10 words and keep it under 60 characters.

4. Stay Specific

In the B2B world, using industry-specific language grabs attention. Subject lines such as “Best CNC Machines for 2023” can help emails perform better than standard business lingo.

Call attention to your deals or offers instead of just saying something general. “Hot summer deals” doesn’t pull as well as “Save 25% on LED Lighting,” for instance. Another thing: a subject line that includes a number is opened 45% more than average.⁴

5. Show Personality

Gimmicks abound in B2C email marketing. But we professionals are more… professional, right? Yes, however B2B email marketing doesn’t have to be stuffy. In fact, showing some personality makes complex industries stand out.

Ask a compelling question. Use a good pun (it is possible). Tease what’s to be found inside. You know your audience, so write something interesting that also shows off your brand’s personality.

6. Go Visual

Subject lines are words, right? However, some visual tricks can help your email stand out. For instance, start the line by putting the first word in [Brackets]. By the way, that is capitalized on purpose; begin all subject lines with a capital letter.

👉Use emojis, wisely. Although emojis are no longer seen as unprofessional, even in business communications, they must be used properly — and sparingly. Use emojis to complement words, not replace them. Your main message must remain clear.

Which emojis are best? The following have worked to increase open rates by the percentages shown, but you may want to discover just the right emoji for your brand or offer using A/B testing:

⏰ = +24%

⏳ = +18%

✔️ = +16%

👀 = +14%

7. Don’t Shout

Hey! You!! See how some visual tricks don’t work? No one wants to be yelled at, and overusing punctuation contributes to that as well as USING ALL CAPS. Those tricks look like spam, especially when additional special characters are used. Soooo KNOCK IT OFF!!! Hee hee.

Examples of high-performing email subject lines

Here are some real life examples of effective email subject lines we’ve used for some of our complex industrial clients. Open rates were well above industry benchmarks and were verified that they were not overly inflated by Apple mail privacy settings.

Is {company name}’s fleet equipped with the right tools?
- This line pushes our maximum 60-character/10-word limit, yet it’s personalized and asks a relevant question.
Just for {company name}: a custom web page
- The personalization is complemented by thoughtful words, creating a caring feeling, and explaining that something unique was made.
{first name}, watch a demo of the {product name}
- Short, simple, and specific, this line personally invites action without needing to invest anything other than a few minutes.
See Shrink Bundling in action 👀
- An invitation that promises something exciting if opened. The emoji is the punchline, not the main grabber.
How to extend tap life 400%
- After being sent to just the right audience, this drove a 42% open rate. When a number is this impressive, just use the results and be done.
What’s your work truck fleet REALLY costing you?
- Another intriguing question that teases that there are better solutions available.
Stay Cool
- Short and sweet, and seasonally appropriate can work to your advantage. This subject line for an IT enclosure client garnered a whopping 46% open rate.
Read this before you license map data or a map API platform
- This subject line speaks directly to a contact who’s evaluating solutions and their need to be accountable for the right choice. It is longer than most but 42% of recipients opened it.
👀 Look Inside {client name}’s Liquid Bottling Services
- An emoji and the human tendency to love sneak peeks and behind-the-scenes content helped this email perform well.
Thank you for stopping by last week
- Given the right situation, a simple message is often the best. This subject line resulted in an open rate of 51%. Next time, we’ll personalize it and compare the results.

That’s the fun part about email subject lines for B2B — the testing! Nothing is ever final, as ongoing improvements can be made to achieve top open rates. Pro tip: if your first email send was a flop, craft a new subject line and re-send it to the people who didn’t open it or click on it yet. That’s the beauty of marketing automation and smart lists in action!

Help improve your overall marketing email health and deliverability by reading our tip sheet: 10 Ways to Improve Your B2B Email Metrics. Click to get your copy now.