What is double opt-in?

Double opt-in

Double opt-in is a two-step email subscription process where new subscribers confirm their interest by clicking a link in a verification email before receiving any marketing messages. The subscriber fills out your form, then checks their inbox and clicks "confirm" to complete their signup.

This extra step filters out fake addresses, typos, and people who didn't actually want to subscribe. You end up with a list of people who genuinely want to hear from you.

How double opt-in works

The process takes about 30 seconds from the subscriber's perspective:

1. Someone enters their email address in your signup form
2. Your email platform immediately sends a confirmation email
3. The subscriber opens that email and clicks the verification link
4. Their status changes from "unconfirmed" to "active"
5. They start receiving your campaigns

Until that confirmation click happens, the contact sits in limbo. They exist in your system but can't receive marketing emails. In ActiveCampaign, these contacts show as "unconfirmed" without the green checkmark next to the list name.

Double opt-in vs. single opt-in

Single opt-in skips the confirmation step entirely. Someone submits your form and immediately becomes an active subscriber. Faster for them, riskier for you.

Single opt-in works well when:

• Speed matters more than list quality
• You're running a time-sensitive promotion
• Your audience is less likely to complete extra steps

Double opt-in makes more sense when:

• Email deliverability is a priority
• You're building a long-term nurture strategy
• You operate in regions with stricter consent requirements

The tradeoff is straightforward: single opt-in grows your list faster but includes more dead weight, while double opt-in grows slower but every subscriber has proven they want to be there.

Benefits of double opt-in

Subscribers who complete the confirmation step engage at higher rates. They opened an email and clicked a link before you sent them anything of value, which is a strong signal of intent.

Your sender reputation benefits too. Fewer bounces, fewer spam complaints, fewer people marking your emails as junk. Inbox providers notice when your list consistently engages, and they reward you with better placement.

Double opt-in also protects against bot signups and malicious form submissions. If someone enters a fake address or a competitor tries to flood your list with garbage, those contacts never activate.

Ready to see how cleaner lists affect your results? Start a free ActiveCampaign trial and test double opt-in on your next form.

When to use double opt-in

Consider your audience and your goals.

High-intent signups benefit most from double opt-in. Newsletter subscribers, course enrollees, and people requesting detailed resources have already shown commitment, so asking them to confirm won't feel like friction.

Lead magnets and gated content sit in a gray area. Someone downloading a free guide expects immediate access, and adding a confirmation step can feel like a bait-and-switch. If you use double opt-in here, deliver the resource on the thank-you page rather than making them wait for the confirmation email.

Transactional contexts rarely need double opt-in. Someone who just bought from you has already confirmed their interest with their wallet.

Is double opt-in required by law?

No universal law mandates double opt-in. GDPR requires clear consent but doesn't specify the mechanism. A checkbox confirming the subscriber understands how their email will be used satisfies the legal requirement.

That said, double opt-in creates a cleaner paper trail. If someone disputes that they signed up, you have timestamped proof they clicked a confirmation link. Some German courts have treated double opt-in as the standard for demonstrating consent, even though it's not explicitly required.

The legal minimum and the smart minimum aren't always the same thing.

How to set up double opt-in in ActiveCampaign

ActiveCampaign enables double opt-in by default on forms that use the "Subscribes to a list" action. To verify it's active or turn it back on:

1. Go to Website → Forms and select your form
2. Click the Options tab in the right panel
3. Find the Form Action box and click the gear icon next to "Subscribes to list"
4. Toggle double opt-in on
5. Save your changes

You can customize the confirmation email from this same settings panel. Make the subject line clear, keep the body short, and make the confirm button impossible to miss.

FAQs

Will double opt-in hurt my list growth?
Some subscribers won't complete the confirmation step, so expect to lose a portion of signups. But the subscribers you keep are more valuable than the ones you lose.

What happens if someone doesn't confirm?
They remain unconfirmed and can't receive marketing emails. You can set up a reminder automation to nudge them, but avoid being pushy.

Can I switch from single to double opt-in on an existing list?
Yes, but only new subscribers will go through the confirmation process. Existing contacts keep their current status.

Does double opt-in affect deliverability?
Positively. Confirmed subscribers bounce less and complain less, which improves your sender reputation over time.

Want to build forms that grow a list worth emailing? Try ActiveCampaign free and set up double opt-in in minutes.