Klaviyo Subscription: benefits ​

A store running the official Klaviyo extension can collect email consent but not SMS consent, and its abandoned-cart links overwrite whatever the shopper had in their cart. This extension closes both gaps and adds a cookie-consent gate on Klaviyo's tracking script.

Key business benefits ​

• SMS marketing consent becomes collectable - The official extension has no SMS subscribe or unsubscribe code at all. This adds it at checkout, on the Create Account page, in My Account, and on the admin customer form, so an SMS list can be grown from the storefront.
• Phone numbers are validated before they reach Klaviyo - Numbers are normalised to E.164 with per-country rules for 22 regions, so a local 07 number or a 10-digit US number is accepted and stored in the form Klaviyo expects.
• The SMS opt-in only shows where it can work - The checkbox is hidden when the shopper's country is not enabled for SMS, so nobody opts in to something the store cannot deliver.
• Abandoned-cart links ask before changing the cart - When a Klaviyo email link arrives at a cart that already has items, the shopper chooses Merge, Replace, or Cancel instead of having the older cart silently merged in.
• Stale cart links are rejected - A quote that is inactive or already tied to a placed order is refused, so an old email cannot resurrect a cart that has already been bought.
• Klaviyo's script respects cookie consent - klaviyo.js is held back until the visitor consents to the cookie group carrying __kla_id, which keeps onsite tracking consistent with the store's cookie banner.
• Consent stays in step with Klaviyo - Magento's newsletter state is reconciled against what Klaviyo reports, so the two do not drift apart as customers subscribe and unsubscribe on either side.

Example use cases ​

• A store adding SMS to an existing email programme - The consent capture is the missing piece; the lists, flows, and sending all stay in Klaviyo.
• Multi-market stores - Allowed countries is set per store view, so each market only offers SMS where Klaviyo supports it.
• Recovering carts without annoying people - Shoppers who have already started a new cart are asked before anything is changed.
• A store under strict cookie compliance - The consent gate keeps Klaviyo's tracking script from loading before the visitor has agreed to it.

What to weigh first ​

• Allowed countries defaults to US and CA - Until that is changed, every European number fails validation and the SMS opt-in stays hidden, with no message to explain it.
• Saving a customer in the admin can unsubscribe them from SMS - Worth resolving before the module goes near a store with an active SMS list.
• Failed subscribe calls are logged rather than shown - The storefront reports success either way, so signups need verifying in Klaviyo.
• The cart merge link empties the cart on a GET request - Worth knowing before the abandoned-cart flow goes live.

The overview page covers each of these with the configuration paths involved.