Single Opt-in vs. Double Opt-in

Two signup methods are available in email and SMS marketing through Mailchimp: single opt-in and double opt-in. Both are easy, secure ways to collect new contact information and engage your audience. You’ll choose which opt-in method you prefer for each audience.

In this article, you'll learn about the 2 signup methods and which one might be right for you.

In email marketing, senders are required to get permission from their contacts before they can send promotional emails to them. Many countries around the world have laws that require permission, or consent, before email marketing communications can be sent. CAN-SPAM in the United States and CASL in Canada are two examples of such laws, and there are many other international anti-spam laws worldwide.

Any time someone fills out a sign-up form that says something like "You agree to receive email marketing from My Company regarding our products and services," we call that "opt-in." The person has opted in to receive content from your company.

The requirements for obtaining opt-in consent vary by country, but they all have one main point in common: you need to get permission from anyone you send marketing email to.

The Importance of Permission
Terms of Use and Anti-Spam Requirements
About Your Contacts

Single opt-in

The single opt-in method is simple. It's probably what most people think of when they sign up to receive marketing emails or text messages. A contact fills out your signup form, clicks submit, and their information is saved in your audience. Behind the scenes, Mailchimp uses the form to save important information such as the contact's IP address and the date and time they signed up.

Single opt-in streamlines the signup process, and it’s particularly useful if people sign up to your email or SMS marketing through a mobile device.

Double opt-in

The double opt-in method has an additional step, but it's still easy to use. It's similar to single opt-in, but includes a verification step where the contact receives an email or text message and has to confirm their signup.

An advantage of the double opt-in method is that you'll know the email address or SMS phone number is valid. We recommend double opt-in if you aren't focused on audience growth, or if you’ve had low open rates or abuse complaints in the past. You may also decide to use the double opt-in method to satisfy regulations in your market or country.

Double opt-in is required to send abandoned cart text messages.

About Fake Signups
About Subscriber Engagement

Choose opt-in settings

Each time you create a new audience in Mailchimp, you’ll choose the opt-in settings you want to use with it. Change the email marketing opt-in method for an individual audience from its settings page. If you have multiple audiences, you can make global changes on the Opt-In Settings page. Change the opt-in method for your SMS Marketing program from the SMS settings page.

To learn which countries have SMS programs, check out About SMS Marketing in Mailchimp.

Customize the signup process for email

As your email contacts move through this process, they may need a bit of guidance. Both opt-in methods use a few related forms and emails to help your contacts along, all of which are fully customizable in the form builder.

• Signup form
  This is the hosted form that all contacts fill out. It is fully customizable to meet your consent obligations under applicable laws, and can be shared or embedded on your networks and websites.
• Signup thank you page
  If you use double opt-in, this is the page a potential subscribed contact sees after they submit your signup form, which thanks them and asks them to verify their subscription in the opt-in confirmation email.
• Opt-in confirmation email
  If double opt-in is turned on, your contacts will receive this email after they submit your signup form. It should represent your brand, and give an idea of what your content will be like in the future.
• Confirmation thank you page
  This page appears after the contact clicks the button in the confirmation email. Use it to say thank you and welcome.

To customize the signup form, emails, and response pages that are part of the signup process, follow these steps.

1. Click Audience, then select Signup forms
2. Scroll down and click the Form builder card, or click Manage forms.
3. If you have more than 1 audience, click the Current audience drop-down and choose the one you want to work with.
4. Choose which item you want to customize from the Forms and response emails drop-down.

That’s it! From here, use the design tools to match your signup form, emails, and response pages with your business needs and brand.

Mailchimp's hosted forms include a reCAPTCHA box that helps filter fake signups, regardless of which opt-in method you choose.

If you use landing page signup form blocks, or embedded or pop-up forms, enable reCAPTCHA in your audience settings.

About reCAPTCHA for Signup Forms
Change Audience Name and Defaults
How the Form Builder Works