B2B email subject lines: Rules, tips, and examples for high-impact campaigns

A subject line is a well-known part of sales outreach — the first thing your prospects see in their inbox. If crafted well, it becomes the ace up your sleeve.

How do you master B2B email subject line creation? What is the fine line between a good and a spammy subject line? Finally, how do you keep up with the industry trends and stay ahead of them?

We will help you explore the topic and share the best subject line examples for your email campaigns. Let’s get started!

Key rules and practices for effective B2B email subject lines

According to Hubspot, 60% of B2B sales involve 2–4 decision-makers, so your subject line has to win the audience over every time.

While B2C focuses on end users, B2B’s target audience includes executives, operational managers, or marketing leads. Why is the difference significant?

Each audience calls for a particular approach, and B2B is no exception. Let’s break down the key rules and practices to craft the best email subject lines:

• be precise and short: According to recent studies, subject lines with no more than 35 characters get the best open rates. Try to make your subject line short and clear;

(Source: Subject line by AiTopTools)

• be careful with punctuation: Research shows that more than 3 punctuation marks can make your cold emails appear spammy. It is best to avoid too many exclamation points, commas, hyphens, or colons;

(Source: Subject line by Make)

• add a question mark: Email subject lines with a question had an average open rate of 20%, while those had a dismal;

(Source: Subject line by KillerStartups)

• try numbers or currency: The same research states that subject lines with currency had a 29% open rate (compared to 13% of those without). The same applies to the numbers: tests with numbers performed 8% better.

(Source: Subject line by MAGNiTT)

Now that you have the tips, here comes the main rule:

How to write B2B email subject lines that get results

Only the most creative ones thrive when it comes to cold email outreach. Before crafting your email subject line, use your answers to these questions as your guideposts.

Have you picked your target audience?

“How is the audience connected to my B2B email subject line?” you may wonder. 

For the subject line to work, you need to carefully plan whom and how you will email. Even offers with the best subject lines remain unopened if they are irrelevant. 

Studies show that the effectiveness of accurate targeting has increased by 14% since 2021. Addressing and mentioning a specific pain point in your subject line is essential.

Once you have selected your target prospects, you can start drafting a few subject line variants. Why a few?

How do recipients benefit from you?

Think of the cold email subject line as a way to demonstrate your product’s value proposition on the spot. Research shows that value marketing is now among the top 5 marketing strategies of focus. If that is your approach, you are on the winning side!

A good subject line resonates with the prospect’s interest or pain points, which makes them click and open the email.

Let’s check some ideas for how to describe the benefits and grab attention:

• showcase a valuable resource: Adding exclusive insights can make your cold email subject line more appealing. You might use a catchy email subject line like “Explore our digest with tips for team productivity” to promote your offer;

(Source: Stripo template)

• talk about events: If you’re hosting a networking event, use intrigue in the subject line;

(Source: Subject line by Web Summit)

• create urgency and use action-oriented language: Highlight what your recipients can get if they open your cold email. Just make sure not to overuse immediate action words.

(Source: Subject line by Pegasystems)

What pain points are you trying to solve?

A whopping 70% of B2B buyers want business suppliers to spend more time trying to understand specific pain points. Do the research and share success stories and insights to build trust. 

Here are examples of B2B email subject lines that focus on the brand’s experience:

1. Success story: How we helped [Company name] save $50K annually.
2. How strategic changes led to 25% cost savings for [Company name]!
3. Case study: A 33% drop in operational costs for [Company name].

(Source: Subject line by Groove HQ)

Your subject line should clearly state what you are addressing and what the benefit is. Show your expertise and be ready to talk in numbers to support your claim.

Is the email subject line personalized?

Here comes the personalization — or, in other words, another chance to grab attention! If you are still unsure whether personalized subject lines work, check out these tips based on advice from industry experts. 

Utilizing variables can help you boost your open rate by 20%.

This is when your research into your audience, particularly relevant contact information, comes in handy. 

Try tailoring the subject line to the prospect’s company and job title or mentioning a mutual connection. It can help your email subject appear more relevant. 

Here are some examples that may inspire you:

1. Is [Specific Pain Point] holding back [Prospect’s Company Name]? 
2. [Your Company Name] can help [Prospect’s Company Name] save up to [XX]%.
3. Learn how [Your Solution] can reduce cost for [Prospect’s Industry]!
4. [Prospect’s Name], you can increase [Prospect’s Company Name]’s revenue by 14% in [Timeframe]!

(Source: Subject line by Salesmeetings)

Conditional or advanced variables are a great option to customize your cold emailing even more. The best subject lines are personalized, so include the prospect’s social media updates or interests where relevant.

Have you adjusted your subject lines to avoid spam filters?

There is a fine line between a spammy subject line and a catchy one. While it is crucial to craft a spicy opening, excessive exclamation points, all caps, or terms like “Free!!!” or “100%” will hurt your email campaign results and can trigger spam filters.

Email providers usually use artificial intelligence to analyze and filter your emails, and they do their job well. 

A recent deliverability test states that 16.9% of cold emails land in spam or go missing. 

Try to stick to these tips when writing your subject lines: 

• avoid spam words: Phrases like “Act right now!”, “Get easy cash” or “Earn $$” discredit your offer. Yes, everyone loves a discount, but your email should sound authentic. Hubspot has a spam words list that can help you avoid these traps;
• avoid caps: Using all capital letters, such as “LAST CALL,” in your email subject lines can reduce the readability of the text. According to Harvard, people may struggle to identify words;
• avoid repetitive symbols: Using repeated symbols, such as “$$$$” or “!!!!”, can turn good sales email subject lines into spammy ones;

Checklist to write a subject line

Now that we have discussed so many tips and rules, let’s sum everything up. A good B2B cold email subject line shows the value and gets straight to the point. 

Here is what you can try:

• focus on a specific benefit;
• address pain points;
• use action language;
• keep your subject line less than 35 characters;
• if you make a promise, keep it;
• personalize and adjust email subject lines.

Remember that whatever practice you try, it has to blend smoothly with the email template. If your offers sound natural, the email opening chances will increase exponentially. 

Tips for optimizing subject lines across different industries

It is time we talk about the inevitable — AI in email marketing. Is it working, or is it just creating tons of low-quality emails? 

AI optimization of cold email subject lines

Numbers speak louder than words. According to another Hubspot report, using AI personalization can increase your ROI by up to 70%. This is exciting news for many marketers utilizing these tools.

Stripo is no stranger to AI technology. You can create and optimize email subject lines right in the template builder:

1. Open the email template you’d like to improve.
2. Click on the Settings button.
3. Choose the Improve with AI option:
   
   
4. Apply any suggested variant or hit the button to retry.

What does this have to do with your industry? You can briefly mention your company’s specialty in the account settings. This will help AI understand your focus and generate subject line variants tailored to your industry’s needs.

Manual optimization of email subject lines

If you prefer to act in the old-fashioned, manual way, this part could be helpful!

Let’s check the average open rates for some industries to see if your cold emails outperform or underperform. As a bonus, you will get subject line tips:

1. Electronics companies have an average open rate of 33.88%.
   
   Subject line tips: Try to focus on the industry pain points, such as environmental regulations, supply chain disruptions, and demand uncertainty. 
   
   Make sure to address these in your cold emails to make the services relevant.
2. The business (marketing and consulting) sphere has a 34.3% open rate.
   
   Subject line tips: You could include exclusive insights on specific markets or data quality solutions that drive results. Industry trends change fast, so tips on where everything is headed and how to get quality data are appreciated. 
3. Software companies’ open rates are as high as 35.92%.
   
   Subject line tips: Focus on easy integrations and unified tools and keep security in mind. Data safety is a big concern in the industry. A significant 29% of sales professionals state they would be more efficient if the number of tools they use decreased — it is your time to shine!
4. The healthcare sector has a 37.39% average open rate.
   
   Subject line tips: If your product offers improvements to documenting workflows or protects patients’ data, include these details in your subject line. According to NetSuite, these are some of the challenges in the healthcare industry.
5. Finance companies have the lowest average open rate of 26.48%.
   
   Subject line tips: TechTrust mentions pain points related to data security, privacy, and regulatory compliance. If you can address these, please do.
6. The real estate sector has a 37.18% open rate.
   
   Subject line tips: Implementing AI, blockchain, and virtual reality are recent industry trends. If your product addresses these topics, include it in the email subject line. 
7. Education companies reach a 37.35% open rate.
   
   Subject line tips: Insights on learning approaches, data privacy, and teacher training might be some pain points for you to consider.

   You might also like

   90 subject line examples for student emails
8. Internet and telecom companies top the list with a 39.96% open rate, on average. 
   
   Subject line tips: If your product improves service (e.g., network quality) or addresses data protection and ethics, include the solutions to these risks in your email subject line.

Examples of successful B2B email subject lines

Having reviewed all the recommendations and industry insights, it is time to check some email templates and cold email subject lines that implement them.

Explore our subscription plans

Subject line ideas:

1. [Prospect’s name], struggling with a subscription plan choice?
2. We hand-picked plans for [Prospect’s company name]. Check a review!
3. [Prospect’s name], here’s our top plan comparison for [Prospect’s company name].

(Source: Stripo template)

Time-saving software

Subject line ideas:

1. [Prospect’s name], how about 10 saved hours a week? 
2. 10 hours off your work time.
3. Cut that time! [Prospect’s name], let’s optimize your hours.

(Source: Stripo template)

What’s new?

Subject line ideas:

1. We listen: Improved interface and expanded product offers.
2. [Prospect’s Name], be the first to test our new features!
3. [Prospect’s Name], you help us become better.
4. What’s new at [Your company name]?

(Source: Stripo template)

Wrapping up

Cold emails are not dead, and good subject lines can become a game-changer for your campaigns. 

Make sure to remind prospects of your benefits and try to understand and address their problems. Offering solutions rather than just selling is a great approach to try.

We hope this article inspired you to create B2B email subject lines that will improve your sales outreach efforts. 

Thanks for making it to the end!