There are three ways to collect SMS subscribers for Instant, and all of them run through Shopify or Instant directly, so there is nothing to connect. Instant only sends SMS to shoppers who have given explicit SMS consent, which is separate from email consent.

Before you start

SMS needs to be configured on your account before any of these will send. If you have not done that yet, set it up in your Instant AI dashboard first. Collecting sign-ups does not depend on it, so you can start building your list now and switch sending on later.

SMS is available in selected regions. Shoppers with a number outside a supported region are still captured, but skipped at send time.

Option 1: Add SMS to your Instant pop-up

Your Instant sign-up pop-up can ask for a phone number as a second step, after the shopper gives you their email.

  1. Go to Configuration > Signup form in your Instant AI dashboard
  2. Click Edit
  3. Add the Phone Capture step to your form
  4. Choose whether shoppers can skip the step
  5. Save and publish your form

The Phone Capture step is disabled by default, so you need to add it manually.

Phone capture is a separate step to email capture, not a second field on the same screen. We keep them apart because splitting the two lifts overall sign-up rates.

Option 2: Build an SMS sign-up landing page with Shopify Forms

Use this when you want a page to send people to, rather than a pop-up that appears on your store. It is the right approach for an “SMS club” page, a link in your bio, or a link inside a post-purchase email.

Shopify Forms is a free app from Shopify. Because Instant reads from Shopify directly, a form built this way needs no integration work.

  1. In your Shopify admin, go to Apps > Forms, and install Shopify Forms from the Shopify App Store if it is not there
  2. Click Create form and select Inline form
  3. Add the Phone field
  4. Turn on SMS marketing consent and set it to require a checkbox, so you have a clear record of the opt-in
  5. Write your Consent disclaimer, covering message frequency, data rates, how to opt out, and a link to your terms and privacy policy
  6. Add a customer tag, for example sms-signup, so you can segment these shoppers later
  7. In the placement step, select Create a landing page, which gives you a URL such as yourstore.com/pages/sms-club
  8. Publish the form, then submit a test number and check the shopper in Customers in Shopify to confirm SMS consent is recorded

Tip: If you are moving off Klaviyo, this replaces Klaviyo’s Embed form. Instead of pasting a code snippet into your theme, the form lives natively in Shopify and Instant picks the consent up from there.

Option 3: The checkout consent checkbox

Shopify can show an SMS marketing checkbox at checkout. This collects consent from shoppers who are already buying, without any extra page or pop-up.

  1. In your Shopify admin, go to Settings > Checkout
  2. Under Customer contact method, enable the SMS marketing option
  3. Save

Consent is only recorded once the shopper completes the checkout.

How these reach Instant

Instant reads SMS consent from Shopify automatically. There is no list to import and no setup step to connect a form.

Once a shopper has SMS consent and a number in a supported region, they are eligible for:

  • Your Welcome Flow, including the SMS touchpoint
  • Abandoned Cart and Abandoned Checkout flows, where SMS sends at touchpoint 2
  • Any campaign with an SMS step

A shopper can be subscribed to SMS but not email, or the other way around. The two subscriptions are managed separately, and unsubscribes are handled per channel.

If you are also collecting SMS consent through Klaviyo or another provider, turn off their SMS flows before you enable the same flows in Instant. Shoppers forgive a duplicate email. They do not forgive a duplicate text.

FAQ

Do I need an SMS provider to collect sign-ups? No. Shopify stores the phone number and the consent on the customer record, and Instant reads it from there. You only need SMS configured on your Instant account to send.

Can I build the sign-up page myself with a custom form in my theme? Not reliably. Shopify’s storefront form supports email marketing consent only, so a hand-built form can collect a phone number as plain text but cannot record SMS consent against the shopper. Use Shopify Forms instead.

Can I use an Instant pop-up for a dedicated SMS landing page? No. Instant pop-ups appear on your storefront and feed your Welcome Flow. For a standalone page with its own URL, use Shopify Forms.

Will shoppers who signed up before I turned SMS on still get texts? Yes, as long as they have explicit SMS consent and a number in a supported region. That includes consent synced from Shopify, from your checkout checkbox, and from an existing Klaviyo list.

Can I offer a discount for signing up to SMS? Yes. Set your coupon in Instant Coupons and it carries through your Welcome Flow. Make sure the offer wording on your Shopify Forms page matches the coupon you have configured in Instant.

Does a Shopify Forms sign-up trigger the Welcome Flow? Yes. Instant treats it as a new subscriber and enrols them, the same as a sign-up from your Instant pop-up.

For more on how sign-ups feed your first flow, see How does the Welcome Flow work?. For SMS in your abandonment flows, see Instant AI SMS in Flows.