Klaviyo Updates SMS and WhatsApp Consent Collection in Shopify Checkout

On October 15, 2026, Klaviyo introduced an update to its SMS and WhatsApp Consent Block for Shopify, a tool for collecting customers' permission to receive SMS and WhatsApp messages directly during the Shopify checkout experience.

Online stores can now use a more flexible subscription block, choose how consent is confirmed, customize the form's appearance, and manage enrollment in two mobile messaging channels through Klaviyo.

One of the main changes is the option to use a checkbox instead of a separate subscription button. This brings the consent form closer to familiar Shopify Checkout controls and reduces the number of actions required from customers.

The update builds on an integration introduced on March 31, 2026, when Klaviyo added WhatsApp consent collection to Shopify checkout and post-purchase pages. The October release expands an existing tool rather than introducing the integration for the first time.

What Is Klaviyo and Why Collect Consent in Checkout?

Klaviyo is a marketing automation and customer communications platform widely used in e-commerce. It brings together customer, order, website behavior, and subscription data so brands can build automated email, SMS, and WhatsApp marketing programs.

Its Shopify integration makes store events available for audience segmentation, personalized messages, and repeat-purchase campaigns. However, having a customer's phone number on an order does not automatically authorize marketing messages. Promotional SMS and WhatsApp communications require appropriate permission, or consent.

Checkout is an appealing place to request that permission. Customers are already interacting with the brand, entering contact details, and completing a purchase. An invitation to subscribe can fit naturally into the process.

Collecting subscriptions on Checkout, Thank you, and Order status pages can grow a brand's first-party audience without a separate pop-up form. Results still depend on the interface, disclosure language, and whether customers want to subscribe. Adding a checkbox does not guarantee higher subscriber counts or sales.

How SMS and WhatsApp Consent Worked Before

SMS subscriptions through standard Shopify settings

Before the expanded app blocks, stores could collect SMS marketing consent through Shopify's native checkout settings. Merchants enabled SMS under Marketing options and configured subscriber synchronization with Klaviyo.

After entering a phone number and consenting, the customer information synchronized with Klaviyo. With double opt-in enabled, the customer also had to confirm the subscription.

This workflow remains available after the October update. Klaviyo's new block is not a mandatory replacement for Shopify's standard opt-in controls.

WhatsApp previously required a separate process

In 2025, the standard Klaviyo integration did not yet support collecting WhatsApp consent directly in Shopify Checkout. Merchants relied on Klaviyo forms, keywords, QR codes, dedicated links, or APIs, making it harder to coordinate SMS and WhatsApp subscriptions during checkout.

On March 31, 2026, Klaviyo introduced WhatsApp Consent on Shopify Checkout. That integration enabled WhatsApp permission collection in the store experience, including consent for marketing and transactional communications. Therefore, WhatsApp support predates the October release.

What Changed on October 15, 2026?

1. Checkbox instead of a subscription button

Previously, customers entered a phone number and clicked a subscription button in the app block. Merchants can now select Checkbox as the sign-up action. The customer enters a number and checks the box, and Klaviyo processes the permission without requiring a separate registration-button click.

If the phone number is missing or invalid, the system displays an error and does not accept the consent. After successful registration, a confirmation appears and the phone input becomes locked.

The checkbox cannot be preselected. Customers must take an affirmative action to subscribe, reducing the risk of accidental opt-ins caused by a prechecked control.

2. One form for SMS and WhatsApp

Merchants can select Text message, WhatsApp, or both, allowing one app block to handle both channels instead of maintaining completely separate forms.

A unified form does not mean that consent automatically applies to every channel or message category. Klaviyo stores SMS and WhatsApp consent separately. A customer may be subscribed to SMS only, WhatsApp only, both, or neither. The disclosure must clearly explain which channels and types of messages the customer is agreeing to receive.

3. Separate transactional and marketing permissions

Klaviyo provides four consent configurations:

• Transactional and marketing: permission for both categories of messages.
• Transactional with marketing as optional: transactional messaging with a separate option to join marketing communications.
• Transactional messages only: transactional notifications without marketing enrollment.
• Collect phone number without consent: collects a phone number without collecting messaging permission.

Collecting a number without consent does not authorize promotional texts. Transactional permission must not be treated as marketing permission: approval to receive a shipping update, for example, does not necessarily authorize discount offers.

With Transactional with marketing as optional, a checkbox-based form may request marketing permission separately. The configuration therefore changes not only the user interface but also which subsequent messages can be sent.

4. More flexible visual customization

The October release adds styling options, including displaying a title as regular text instead of a prominent heading, removing the block border, and editing interface copy.

These options help the form blend into Checkout. A minimalist one-page checkout may not benefit from a large heading and an extra border surrounding a subscription option. Merchants can remove those elements, although any impact on sign-up or checkout completion rates should be measured rather than assumed.

Where the Consent Block Can Be Placed

Klaviyo supports three Shopify page types, but availability depends on the merchant's Shopify plan:

On Shopify Plus, merchants can place the block directly inside Checkout. Merchants on non-Plus plans can use eligible Thank you and Order status pages but should not assume they have the same in-checkout placement permissions. This distinction matters particularly for smaller stores.

How to Set Up the SMS and WhatsApp Consent Block

Step 1. Verify the Shopify and Klaviyo integration

Enable the relevant SMS or WhatsApp capabilities in Klaviyo, connect Shopify, and enable onsite tracking. Check country availability and sender setup for the messaging channels you plan to use.

Step 2. Create the block in Klaviyo

Navigate to Audience → Growth tools → Collect subscribers on Shopify → Manage, then select Create or Create app. Choose Text message, WhatsApp, or both, and name the block, for example, “Shopify Checkout SMS & WhatsApp Opt-in.”

Step 3. Choose a subscriber list

Select the Klaviyo list that should receive marketing subscribers. Verify whether the list uses single or double opt-in. If double opt-in is enabled, subscribers must complete the additional confirmation required for the channel. Transactional subscribers are not automatically added to the marketing list.

Step 4. Configure consent categories

Choose whether the store intends to send marketing messages, transactional messages, or both. Then configure the disclosure text explaining subscription terms. The copy must reflect the actual messaging program and applicable country and channel requirements.

Step 5. Choose Checkbox or Button

Under Sign-up action, select Button for an explicit button click or Checkbox for affirmative opt-in through a checkmark. With Checkbox, make sure the adjacent language clearly explains what the customer is agreeing to.

Step 6. Customize the appearance

Edit the title, phone-field label, error copy, and success message. Remove the border or change the heading style if needed. Save the block and copy the resulting App Block ID.

Step 7. Install the app block in Shopify

Open Shopify's Checkout editor, select the supported page, and choose Add block → Opt-in at checkout. Paste the App Block ID generated in Klaviyo. Enable Shop Pay integration if appropriate, save, and run a test checkout.

Step 8. Test the consent records

Test SMS-only permission, WhatsApp-only permission, permission for both channels, and the choice not to subscribe to marketing. Also verify phone validation, double opt-in, and the consent statuses in Klaviyo customer profiles.

See Klaviyo's official setup instructions for current interface details.

What to Do With Shopify's Existing SMS Checkbox

If a store already collects SMS consent through Shopify's standard opt-in, adding the Klaviyo app block may create duplicate subscription controls. This can confuse customers and make it unclear which messages they are authorizing.

Klaviyo recommends considering disabling Shopify's native SMS checkbox on Shopify Plus when the new app block collects the same marketing permission.

The setting is under Shopify Admin → Settings → Checkout → Marketing options → SMS. The synchronization of Shopify Text Message subscribers to Klaviyo can remain active so subscribers collected through other Shopify mechanisms continue to sync.

Using SMS and WhatsApp Consent for Segmentation

Once consent is collected, Klaviyo stores it in customer profiles alongside email, phone number, order history, and audience segments. SMS and WhatsApp remain separate channels, each with its own permissions.

For customers subscribed to both channels, a merchant can build combined journeys, sending selected notifications through WhatsApp and others via SMS, provided the permissions and platform policies allow it.

WhatsApp should not be assumed to be universally cheaper or more deliverable than SMS. Economics vary by country, pricing plan, message category, and other factors.

Why the Update Matters for E-commerce

Growing a first-party subscriber base

Stores increasingly value channels that let them reconnect with customers without purchasing every new advertising impression. SMS and WhatsApp can support this strategy when customers grant appropriate permission. Checkout creates another opportunity to collect these subscriptions.

Supporting repeat purchases

Existing customers can receive relevant communications about new products, replenishment, or repeat purchases. A cosmetics brand, for example, may invite buyers to subscribe to product launches or special offers. Marketing campaigns are permitted only through channels the customer has actually opted into.

Improving post-purchase messaging

Customers may value order confirmations, shipping updates, and delivery notifications. Collecting transactional consent separately helps organize these communications. WhatsApp may require Meta-approved message templates, while SMS has its own rules and restrictions.

Coordinating multiple channels

Businesses using email, SMS, and WhatsApp need a unified customer profile with distinct permissions for each channel. Klaviyo supports shared profile data and segmentation without merging different consent statuses. The release therefore improves not only the Checkout UI but also the broader customer communications workflow.

Localizing Consent Blocks for Shopify Markets

International stores can create different versions of the consent block for individual Shopify Markets. For example, a business may use one disclosure for U.S. buyers and another for customers in France.

The merchant clones the block in Klaviyo, translates its copy, and assigns the corresponding App Block ID to the appropriate market in Shopify.

Localization is configured at the Shopify Market level, not automatically for every language. If one market contains multiple languages, customers may see the same block unless the merchant designs a more elaborate solution. Market-specific Checkout customization also requires an eligible Shopify plan, such as Advanced or Plus.

Limitations and Compliance Considerations

Despite the improved interface, collecting mobile messaging consent remains a sensitive part of marketing operations.

• Consent must be explicit. Possessing a phone number does not authorize promotional messaging.
• SMS and WhatsApp consent are distinct. Subscribing to one does not automatically authorize the other.
• Marketing and transactional communications are different. Order notifications do not necessarily establish permission for promotions.
• Checkboxes must not be prechecked. Customers need to actively consent.
• Feature availability varies. In-checkout placement depends on Shopify Plus, while mobile messaging depends on Klaviyo account and channel availability.
• Regulations differ by country. Merchants must consider privacy law, mobile marketing requirements, and WhatsApp Business policies.

How to Measure the New Consent Block's Performance

Evaluate the consent block separately from overall store conversion. Useful metrics include:

Pay particular attention to whether the extra form harms checkout completion. A checkbox might increase the number of subscriptions, but crowded Checkout layouts or unclear disclosures can also discourage customers from finishing their orders. Where feasible, test copy, placement, and design without weakening the quality or legality of consent.

Conclusion

Klaviyo's October 15, 2026 update expands SMS and WhatsApp consent collection options on Shopify pages. Its main innovation is not the arrival of WhatsApp in Checkout, which was introduced in March, but greater control over how subscriptions are requested and displayed.

Merchants can choose Checkbox instead of Button, customize block styling, manage transactional and marketing permissions, and collect consent for both mobile messaging channels through a common interface.

For online stores, this is another tool for developing first-party customer audiences and multichannel communications. Results depend on more than form design: the quality of consent, accurate Klaviyo synchronization, compliance with platform requirements, and the ongoing strategy for customer engagement all matter.

Sources

1. Klaviyo: What's New, SMS and WhatsApp Consent Block on Shopify (October 15, 2026)
2. Klaviyo Help Center: Collect SMS and/or WhatsApp Consent on Shopify Checkout Pages
3. Klaviyo Help Center: Collect SMS Marketing Consent at Checkout on Shopify
4. Klaviyo Help Center: Understanding WhatsApp Consent Collection
5. Shopify Help Center: Editing Checkout Form Options