Single opt in vs Double opt in soi doi

Single Opt-In vs Double Opt-In: What Should You Consider

With a return on investment (ROI) of 4200%, email marketing is one of the most effective strategies to skyrocket your business revenue. No wonder 64% of small businesses leverage email marketing to target their customers! Let’s take a look at how much ROI various industries using email marketing acquire:

single vs double opt in Email ROI by industry 2020


Iit is vital to maintain a subscriber list to use email marketing for scaling your business. How can you do that? By creating single opt-in or double opt-in forms. 

So, which one is better among the two options mentioned above? Both have their share of pros and cons. 

This post will walk you through the nitty-gritty of single opt-in vs. double opt-in. We will also throw light on the differences between the both so that you get the hang of which option will suit your business more.

Let’s get going.

Single Opt-Ins vs. Double Opt-ins: What’s the difference?

As the name itself suggests, single opt-in is a method where your customers become your subscribers when they submit their email addresses to you. On the other hand, the double opt-in process requires your customers to verify their email addresses once they have signed up. 

Let’s take a closer look at double opt-in vs. single opt-in. 

Single opt-in

Businesses use a single opt-in form to let customers sign up to their email list instantly. The customers don’t need to verify their email address and start getting a brand’s email directly. 

Double opt-in

A double opt-in requires customers to confirm their email id once they have filled the subscription form. The customers receive a link on their email, and only when they confirm that they want to receive a brand’s email, they get the emails. 

Single Opt-In vs. Double Opt-in Examples

For instance, if you want to receive healthy living tips, you can sign-up for Healthline’s newsletter. This is what the sign-up form looks like:

single opt in form example Healthline


Once you enter your email address, you start receiving the brand’s newsletter. 

single opt in email templates from Healthline

So, you see, how there’s no other email that confirms your email or asks you if you wish to get their newsletters or not. Simply put, you at once become a part of their subscriber list. 

Here’s what a double opt-in email looks like:

BEE double opt in welcome email sample


It is a confirmation email from Email Design. When brands enable double opt-in, a subscriber, as mentioned in the email above, must confirm their email address for receiving the emails. 

Benefits of single opt-in

Hassle-free process

Since users get subscribed to your emails by simply putting their email addresses in, signing up through a single opt-in is easy and seamless. The customers do not need to go all the way to open their inbox and click on the confirmation email. 

Sure, confirming an email address isn’t a big deal. It won’t take much time either. But, going an extra step might not interest everyone. Imagine a potential subscriber having an inbox full of emails. 

The chances of your confirmation email being lost in the piles of other emails become higher. Hence, a single opt-in saves you from losing a potential subscriber and increases the organic traffic to your website. 

Let’s take an example of a case study from Cirque de Soleil. The brand used double opt-in to create its email list. Results? While 80% of potential subscribers who signed up for the email went ahead and confirmed their email address, one out of every five potential subscribers didn’t confirm their email. 

The bottom line is the conversion rate for Cirque de Soleil could have been even higher had it opted for a single opt-in. 

Also, according to a study conducted by MailChimp, a vast 61% of potential subscribers do not complete the double opt-in signup process. 

Instant email list growth

As mentioned above, the extra step in the double opt-in process reduces the number of potential subscribers that you can have in your email list. 

However, that’s not the case with a single opt-in. All a subscriber needs to sign up for your email and become a part of your email list. No wonder that, according to research from GetResponse, marketers witness 20-30% higher list growth with a single opt-in.

Disadvantages of single opt-in

Low deliverability rate

Do you know spam messages account for 45.1% of email traffic? That’s huge! 

global spam percentage in email traffic single vs double opt-in

Since you brought your subscribers on board in your email list without getting their confirmation, the chances of your email being reported as spam increases. 

In other words, if people will get emails from brands they are not interested in, they will either unsubscribe or mark them as spam. However, since putting an email in spam is more effortless than unsubscribing, 43% of people label it as spam. 

subscribe vs unsubscribe stats on charts single vs double opt in

What if a subscriber mistyped their email address? Or what if someone gave a fake email address just to download your free e-book or industry report? 

All the emails you send to these addresses will either bounce or end up in the spam folder. This, in turn, damages your sender reputation and decreases your brand’s credibility in the long run.

Waste of money

You already know that email marketing generates an ROI of 4200%. However, you can reach that kind of ROI only if you do email marketing the right way. 

In a single opt-in, you send emails to anyone and everyone in your email list. This certainly increases your email sending costs. How? Email Service Providers (ESPs) charge in three ways:

  • Based on the number of subscribers you have on your email list
  • Based on the number of emails you send
  • ESPs consider both the outcomes mentioned above and then charge you

So, whatever the case, if your email is not reaching the right people, bouncing, or ending up in spam, there’s no use investing in email marketing. You will only end up wasting money while getting no Return on Investment (ROI). 

Benefits of double opt-in

High-quality leads

Since potential subscribers try to confirm their email address in double opt-in, it shows they are willing to receive emails from you. This, in turn, gives you access to such subscribers who are interested in your brand. 

Simply put, you get access to high-quality leads and increase your chances of converting them into your loyal customers through top-notch email marketing strategies such as sending welcome emails to new subscribers, personalizing your emails, and more. 

Quick fact: 79% of welcome emails are double opt-in.

welcome emails stats for double optin

Decreased unsubscribe rate

Double opt-in makes the churn-out rate less. When people want to receive your email in their inbox, they won’t unsubscribe. Of course, that includes delivering what you promised them. 

For instance, if you have a content marketing agency and promise your subscribers to give them regular tips and insights on content marketing through your newsletter, you must stick to it. Say if you start promoting your agency all the time instead, your subscribers might lose interest in your emails and unsubscribe to them. Also, to keep your subscribers hooked to your email, make sure you keep your content unique and steer clear of plagiarism.

Improved deliverability rate

Since double opt-in is all about sending your emails to the right people, the spam rate would naturally decrease, improving your email deliverability rate. It will also strengthen your IP’s credibility and effectiveness. 

Is double opt-in required by law?

Data privacy regulations such as the California Consumer Privacy Act (CCPA) and EU General Data Protection Regulation (GDPR) make it mandatory for businesses to handle their customer’s data safely. 

Both the regulations strive towards protecting the consumer’s data. While adhering to CCPA is mandatory for businesses who have customers in California, following GDPR is essential for companies who have customers in the European Union.


The regulation entitles Californians to know the kind of personal information businesses collect. It also lets the people of California opt-out of their data collection or sale.


The regulation stresses “informed consent,” i.e. businesses should market their products online only to customers who have opted for it. Simply put, the consumer should give a willing consent and must be informed without any ambiguity about the kind of personal information the business will share,  

Now, the question: is double opt-in required by law? The answer is no. Choosing a double opt-in for your email marketing campaign is not mandatory. 

You can easily follow all the rules of GDPR and CCPA without double opt-in. Make a checkbox in your single opt-in form that clearly states the kind of information you will use and if they are comfortable sharing it with you. Also, you can give them an easy option to unsubscribe by placing unsubscribe links properly to help them opt out of your marketing email at any moment.

In other words, as long as you are being legal and taking consent from your customers, a double opt-in is not at all a necessity.

Here’s how companies across the globe are using double opt-in:

international usage of double opt in vs single opt in

Single vs. double opt-in: final verdict

By now, you are well aware of everything related to single and double opt-in. So, what do you think is better? Which one outweighs the other? The answer is: it depends on your business and its goals. Both are good in their way. 

In fact, according to a global poll by Litmus, 53.5% of email marketers use single opt-in, and 46.5% are inclined towards double opt-in. 

soi vs doi single vs double opt in donut chart

So, you see, there’s a marginal difference between the usage of both. Hence, choose the one that best suits your business needs. If instant email list growth is your requirement, go for a single opt-in. If having high-quality leads is a part of your marketing strategy, choose double opt-in. 

In either case, clean your email list every 6-12 months. You can use standalone email validation services. Some email marketing providers have them built-in or they provide it via integrations. 

A single opt-in strategy for small businesses and young startups trying to establish their foot in the market will help them promote themselves to a more extensive customer base. 

However, for industry giants and established businesses, double opt-in can be the right way to go with their email marketing strategy. After all, they already have a name in the market. So, it is more about garnering subscribers who are genuinely interested in their business and who can help them increase their sales and revenue.

If you still have second thoughts on which opt-in strategy to choose, try testing both. Use single opt-in for a month and double opt-in for the next. If your deliverability rate, open and click-through rate, engagement, and conversions are fine with a single opt-in, stick to it. If that’s not the case, go for double opt-in. 

Frequently Asked Questions (FAQ)

Double opt-in is a two-way email confirmation process. It requires the customers to confirm their sign-up by clicking on a link sent to their email address after filling out a form. On the other hand, a single opt-in requires a business to just get your email address with the signup to add you to their email list. 

If generating high-quality leads is your goal, a double opt-in is worth your time, money, and efforts. It can also work great for your business if you want to improve your email deliverability rate and keep your sender reputation and credibility at a high level.

A single opt-in is a one-way subscription process where the customers become a part of a business’s email list as soon as they submit their email address in the sign-up form of the business.

No, double opt-in is not required by law. Regulations like GDPR and CCPA strive towards informed consent and customer information protection. As long as a business makes these aspects clear in its sign-up form, there is no legal obligation to go for double opt-in.

Adela Belin

Adela Belin is a content marketer and blogger at Writers Per Hour. She is passionate about sharing stories with the hope to make a difference in people's lives and contribute to their personal and professional growth. Find her on Twitter and LinkedIn.