How to ask for SMS consent within an email

Estimated 5 minute read

|

Updated Aug 6, 2025, 12:00 AM EST

Table of contents

You will learn

Learn how to send a message to your existing email subscribers encouraging them to opt in to SMS marketing. By following this process, your email subscribers will be able to sign up for SMS marketing with just a few clicks.

You can collect SMS consent via email in targeted campaigns or within flows. For instance, post-purchase flows are an effective place to advertise your SMS program and gather sign-ups.

Before you begin

Before you start, make sure you’ve:

To collect SMS consent from your existing subscribers, we recommend taking 3 steps:

  1. Create an embedded SMS sign-up form.
  2. Embed your sign-up form in a landing page on your website.
  3. Send a campaign encouraging email subscribers to sign up for SMS.

Create an embedded sign-up form

Start by creating a sign-up form and designing it to match your brand.

  1. Navigate to Website > Sign-up forms, click Create form, then select Create blank form.
  2. Choose a descriptive form name, like SMS Sign-ups from Email.
  3. From the Choose a list dropdown, select your SMS list (e.g., “SMS Subscribers” or “SMS List”).
  4. From the Choose a form type menu, select Embed.

The modal to create a new signup form

The modal to create a new signup form

  1. Click Save and design.
  2. Delete the Email block in the default form.
  3. Click Add content in the sidebar to open Add blocks.
  4. Drag a Phone number block into your form. Select the block, choose Text message as the channel, and select Single step - Promotional only as the consent type.
  5. Review the disclosure language and check that it includes your business details and links to your mobile terms of service and privacy policy.
  6. Click Targeting & behavior in the menu on the left.
  7. Under Targeting, select Show to all audience members. Under Display, set Devices to All devices.
  8. In Display, copy the code from Embed code. You’ll need it for the landing page in the next section.

An embedded form's embed code

An embedded form's embed code

  1. Once you’ve designed and customized the form, click Publish or schedule, then Publish now.

A user click's Publish on a signup form

A user click's Publish on a signup form

Embed your sign-up form on a landing page

  1. Open your website’s admin and create a new landing page, custom page, or blog post.
  2. Paste the code snippet from the prior section into your new page’s code (often indicated by a </> or Source button).
  3. Save and publish your new page, then open its public URL to check that the form appears and accepts sign-ups on desktop and mobile. Copy the URL for the following section.

If Klaviyo sends a confirmation text after someone submits the form, they must follow its instructions to complete their SMS subscription.

Send a campaign encouraging email subscribers to sign up for SMS

Create an SMS sign-up button in your email

First, create an email template. Once you've designed your template:

  1. Drag a Button block into the template.
  2. Under Button text, enter descriptive text like Sign up for SMS.
  3. In the Link address field, add the URL for the landing page you created in the last section.

The button settings for a button block in an email

The button settings for a button block in an email

  1. Click Exit to save your changes and leave the template editor.

Create a segment of potential SMS subscribers

When your email is ready to send:

  1. Navigate to Audience > Lists & segments > Create > Segment.
  2. Name your segment something descriptive, like Subscribed to email but not SMS. If a naming panel appears, click Create segment to continue to the segment builder.
  3. Create a segment with the definition If someone can or cannot receive marketing > can receive > email marketing > Because person > subscribed AND If someone can or cannot receive marketing > cannot receive > text message marketing > Because person > never subscribed.
  4. Click Create segment to save the segment.

Send your campaign

  1. Navigate to Campaigns > Create campaign.
  2. Name your campaign, select Single channel if prompted, choose Email, and click Continue.
  3. Choose the segment you created above (e.g., Subscribed to email but not SMS) under Send to.
  4. Click Next.
  5. Add a subject line and review the sender name and email address.
  6. Click Email: saved.
  7. Select the template you created previously and click Use template.
  8. Click Next, then review and send your campaign.

In addition to sending this message to your existing email subscribers, consider adding it to your email welcome series as well. Just make sure to add the following under Additional filters for the message: If someone is or is not consented to receive text messages > is not.

Alternative method: add a click-to-text banner to a campaign

Note that this approach is designed to automatically open a text message, but it will not work with Gmail or in Microsoft Outlook; however, everyone can see the banner and manually text your number to subscribe, regardless of their inbox provider.

A click-to-text banner opens a text message with an opt-in keyword when a recipient clicks it on a supported mobile device. The recipient must send the message and complete any confirmation requested to subscribe. To use this functionality, you’ll create 2 versions of your call-to-action: one for desktop users and another for mobile users.

Use a sending number that can receive text messages. Branded sender IDs cannot receive replies, so use the embedded-form method above if you send with a branded sender ID.

  1. Add a Text block to your email template.
  2. Add the following text to your text block:
  3. Text subscribe_keyword to sending_number.
  4. Replace subscribe_keyword with a subscribe keyword from your account (e.g., JOIN).
  5. Replace sending_number with your sending number.

A click-to-text banner followed by disclosure language

A click-to-text banner followed by disclosure language

  1. Within Display > Visibility, click Desktop to set the block to only show on desktop.

A block set to mobile only in Klaviyo's template editor

A block set to mobile only in Klaviyo's template editor

  1. Click Add content, then drag an HTML block into the email for the mobile version of the banner.
  2. In the HTML block’s Display > Visibility settings, select Mobile.
  3. Open the HTML block’s Content tab to edit its code.

The source code button in Klaviyo's email template editor

The source code button in Klaviyo's email template editor

  1. Replace the HTML block’s content with the code below:
  2. &lt;a href=“sms:+sending_number?&body=Send%20this%20text%20to%20subscribe%20to%20SMS%20Updates!%20%28ref:JOIN%29”> Text JOIN to sending_number &lt;/a>
  3. Replace both instances of sending_number with your SMS sending number. If you use a subscribe keyword other than JOIN, replace both instances of JOIN with that keyword, including the one in ref:JOIN.
    • For a toll-free number or long code, the first instance should include the country code followed by the full number, with no dashes, spaces, or parentheses. For example, a US number uses 1 followed by 10 digits: 16171110000. For a short code, remove the + from the link and use the short code without a country code.
    • The second instance of your sending number may include formatting characters: (617) 111-0000

The code for a click to text banner in an email

The code for a click to text banner in an email

  1. Click outside the HTML block to finish editing it.
  2. Add disclosure language to the banner or within the email.

A click-to-text banner followed by disclosure language

A click-to-text banner followed by disclosure language

  1. Create a segment of your email-only subscribers with the following condition: If someone can or cannot receive marketing > can receive > email marketing > Because person > subscribed AND If someone can or cannot receive marketing > cannot receive > text message marketing > Because person > never subscribed

Click Exit to save your template. Then send your email to your email-only subscribers using a campaign, or add the message to your email welcome flow.

Review your results

To keep track of your new SMS subscribers, navigate to Analytics > Metrics > Consented to Receive SMS. Here, you can review your subscriber trends and understand who is opting in to SMS. Learn more about understanding your subscribers in Klaviyo.

Additional resources

Learn how to create and send an SMS campaign in Klaviyo. Note that the process is almost exactly the same for MMS campaigns. The only difference is that you add an image or GIF during the content creation stage. - Migrating from another SMS provider to Klaviyo

Learn the steps for migrating from another SMS provider to Klaviyo. - How to upload a list of SMS contacts

Find out how to add and remove SMS transactional or marketing consent in Klaviyo. Importing your SMS subscribers is an essential part of migrating providers or simply consolidating your data. - The benefits of SMS

Was this article helpful?

YesNo

Use this form only for article feedback. Learn how to contact support.

Explore more from Klaviyo

Community

Connect with peers, partners, and Klaviyo experts to find inspiration, share insights, and get answers to all of your questions.

Visit Community

Partners

Hire a Klaviyo-certified expert to help you with a specific task, or for ongoing marketing management.

Hire a partner

Support

Access support through your account.

Email support (free trial and paid accounts) Available 24/7

Chat/virtual assistance Availability varies by location and plan type

Log in