Single Opt-In vs. Double Opt-In: Which is Best for Your Email List?

single opt-in

Opt-in is the subscription method every email marketer uses on their mailing lists. Two signup methods are available in email marketing: single opt-in and double opt-in.

Do you know which option makes sense for your business?

This is one of the first decisions you’ll need to make in order to initiate an email marketing campaign. And it’s no easy decision to make.

Before your prospects can read your emails, they’ve got to subscribe. And in this article we’ll discuss both methods and what fits your business best so you can make an informed decision.

As you’ll see, whether you choose single opt-in or double opt-in has important implications. It influences list growth, subscriber engagement and conversions.

Ask yourself, what are your objectives?

It’s vital that you look at all of the angles and weigh the pros and cons of each approach.

Let’s begin, shall we?

Note that it is not necessary for a business to have a single type of opt-in across its mailing lists.

What’s the Difference Between Double Opt-In vs. Single Opt-In?

The fundamental difference is that a single opt-in doesn’t require a confirmation, and a double opt-in does require a confirmation.

A single opt-in is a one step process. It only asks a person to enter their email address one time in the signup box on a website.

No confirmation is required, and they instantly become a subscriber.

This process does not require the owner of the email address to confirm that it was in fact them who actually requested to register for the newsletter.

As soon as they enter their email address and fill in all required fields, they start receiving the communication of the brand.

single opt-in

On the other hand, a double opt-in involves a two-step process where a person first enters their email in the signup box.

But after that, they receive a confirmation email where they must click to confirm that they want to subscribe before being added to the list. Basically, your audience is explicitly and conscientiously choosing to be added to your list.

single opt-in

Benefits of Single Opt-In

1. Fast list growth

One huge benefit of single opt-in is that when a subscriber signs up, they’re immediately on the list. There are no other actions mediating subscription.

That allows you to grow your list fast.

Plus, you are connected with new subscribers way quicker than with double opt-in. The confirmation email can hit the spam folder, for example.

While you get quick results, your audience gets instant gratification of being added to your list. And you don’t need to worry about unconfirmed subscribers which equal lost leads.

2. Easy-peasy

Rather than having to look for a confirmation email, open it and click on the confirmation button, a single opt-in only requires the user to enter their email address. Once.

While it may not seem like a big deal to confirm that a person wishes to subscribe, it does create some additional steps. Not everyone is a fan of that.

Or the confirmation email may be lost or forgotten about. Creating an extra step means that a considerable percentage of people will never make it to your email list.

In fact, MailChimp conducted a study and found that 61 percent of people never completed the double opt-in signup process. That’s a lot.

According to their analysis, the primary reason was due to many people no longer anticipating the confirmation message.

But if you use a single opt-in fewer subscribers will get lost.

Disadvantages of Single Opt-In

1. Low lead quality & harassment

Single opt-in raises the risk of having a mailing list of low-quality leads.

For example, third parties could be adding users to your database who did not personally provide their email address. This brings you into conflict with applicable consumer protection laws regarding personal information and commercial solicitation.

In this situation, you’ll be getting more spam complaints due to deliberately wrong email addresses. Moreover, it leaves your subscribers unprotected and exposed to malicious practices.

2. Lower deliverability rates

Compared to double opt-in lists, a considerable number of single opt-in type mails don’t make it to the inbox.

That’s really bad for business in the long run.

Let’s say people change their mind about signing up. Rather than simply unsuscribing, they may identify your email as spam.

According to Litmus, 43% of people mark emails as spam, and half the time it’s because it’s easier to do that than to unsubscribe. Ouch.

3. Sender reputation might be affected

Single opt-in lists need more maintenance than double opt-in lists. Spam and hard bounces must be cleared out of the database regularly.

Keep in mind that people who want to grab your lead magnet, but don’t actually want to be your subscribers will type in any fake address. When you send emails to these addresses, and they bounce, that affects your sender reputation and future deliverability.

Also, open rates and engagement run low in these lists. The rate at which users subscribe to lists does not reflect an all-time-high record of engagement.

4. Typos might cost you subscribers

Not everyone has activated AutoFill forms. 

So, mistakes are bound to happen.

To avoid this, you can ask users to confirm their email address by typing it a second time. If there is no match between the two, the user will know to make corrections.

Note: Email service providers bill you for either the number of subscribers on your list, the number of emails you send or both. So, if your list is full of fake or spam emails, you’re wasting money on sending out emails that bring you anything.

5. Free gated content does not equal quality leads

If you publish premium content that is gated, those who want to download it directly from your site could just enter a random or fake email address.

You can’t do that in double opt-in lists. There, users will first receive an email to verify their account and only then can they download the content.

Benefits of Double Opt-In

1. Bounce-free

Double opt-in tends to enhance the quality of your lists. Even though your list probably won’t grow as quickly, the quality of your subscribers will be higher. 

As a consequence, you’re likely to see a higher open-rate and increased engagement.


Because everyone was interested enough in your newsletters to confirm their subscription. That should make them more responsive to your emails, and more likely to open and click.

Therefore, with double opt-in you get lower bounce rates, zero risk of bad email addresses and no unsolicited emails to uninterested individuals.

Plus, confirmed subscribers are less likely to report your emails as spam. Too many spam reports can really affect your sender reputation and hurt email deliverability.

This is something to avoid at all costs. Poor sender reputation could stop your emails from reaching subscribers at all.

Luckily, since subscribers are likely to be engaged, using double opt-in can actually enhance your sender reputation.

2. High-quality leads

Double opt-in and high quality leads go hand in hand. There is no place for spam addresses in your lists. With double opt-in, everyone must confirm their business.

A database free of non-responsive addresses is more valuable to you since it consists of people who demonstrated real interest.

Those who have interacted twice with your business to confirm their subscription to your newsletter are clearly engaged.

You’ll know for sure the email address is for a valid, monitored inbox. This helps you avoid paying for the delivery of your email marketing campaigns to non-existent email addresses and people who aren’t interested in what you have to say.

Using double opt-in is also a great way to keep your email list clean. And since all list members are confirmed, it gives you more accurate subscriber data.

3. A Lower Unsubscribe Rate

By using double opt-in you’re ensuring that the people who receive your emails really want them. Therefore, you can expect that fewer people will unsubscribe from your email list.

While there’s a bit more involved getting people signed up compared to single opt-in, your leads should stick around for longer and you’ll have less churn.

Because users are expecting your confirmation email they’ll know to look for it in the Spam folder.

This way, you are marked as a contact and your email marketing can get to work.

4. Improved Deliverability

Although spam volume dropped considerably over the past few years, it still accounts for the majority of emails people receive.

As a result, ISPs are more persistent than ever about filtering out anything that could be deemed as spam.

Along with that, many people are quick to flag a message as spam. Which is understandable considering all of the scams and phishing attacks that are happening these days.

In addition, many people who want to unsubscribe will simply flag a message as spam because it’s quicker and easier than looking for the unsubscribe link. Especially if it’s kinda hidden.

If only a small percentage of your subscribers are opening and engaging with your emails, it will inevitably reduce your IP’s credibility. In turn, you run a higher risk of your emails being sent to spam.

But going with a double opt-in, the increased open and engagement rate increases the credibility of your IP and reduces the number of times your messages are flagged as spam by recipients.

So in the long run, you can expect a higher deliverability rate.

Disadvantages of Double Opt-In

1. List growth takes more time

Building a marketing database on the basis of double opt-in will take longer.

But you can use automation in your favor and compensate.

You must make sure that your automations do not clutter the subscriber’s inbox or annoy them. To avoi that you should regularly review the user experience.

Put yourself in your audience’s shoes and check your overall inbox experience.

2. Oops, forgot to confirm

Double opt-in creates a longer signup process for subscribers. The more steps there are, the more likely it is that some people won’t complete them.

What if your audience doesn’t check their mailboxes regularly?

Plus, people might get caught up in something else and forget about the confirmation email from you.

Or they could ignore it altogether. 

To catch their eye and make them look for your email, you could notify them upon entering their data that they’re in for a discount as soon as they verify their link. They’ll confirm their email and who knows, maybe even purchase.

As soon as the user enters their email they should be redirected to a landing page, reminding users to check their email. Offer your audience an in incentive and showcase the importance of confirming their email.

Make sure the confirmation email is triggered within seconds. You have to be fast.

Keep the confirmation email as short and sweet as possible. What’s important is for them to click. If they confirm, you’ll have time in future emails for other call to actions.

Choose your strategy

This discussion is not about this is bad and that is good.

It’s all about your priorities. Both single and double opt-in have their benefits.

If rapid growth is your primary goal and you want to build your list as quickly as possible, then a single opt-in is your best bet. Maybe you don’t have leads coming in from other sources and can’t afford to give it some time.

But if you’re more concerned with the quality of your leads and want a list that’s highly engaged, then a double opt-in would be ideal.

While your list won’t grow quite as fast, you can be certain that your subscribers are genuinely interested in your brand. Therefore, you can expect a higher open-rate and increased engagement levels.

I would recommend doing a bit of experimentation to see what works best. You’ll have your answer in no time.

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