> ## Documentation Index
> Fetch the complete documentation index at: https://storekit.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Marketing Consent and List Subscription

> Turn on the storekit checkout marketing opt-in so customers who tick it are subscribed to your Klaviyo list for email and SMS, and understand who is and is not subscribed.

storekit only subscribes people who asked to hear from you. When a customer ticks the marketing opt-in box at checkout and places an order, storekit subscribes them to the Klaviyo list chosen on that store. Customers who leave the box unticked still appear in Klaviyo with their order history, but are not subscribed.

## Turn On the Opt-In Box

<Steps>
  <Step title="Open General">
    Go to **Stores** → your store → **Settings** → **General**.
  </Step>

  <Step title="Enable Marketing opt-in">
    Turn on **Marketing opt-in** and set the **Checkbox label** to wording that matches how you plan to contact them, for example "Save my details to keep up to date on news and special offers".
  </Step>

  <Step title="Choose the list">
    Go to **Settings** → **Integrations** → **Klaviyo** and pick a list under **Lists**. Click **Save**.
  </Step>
</Steps>

<Note>
  If no list is selected under **Lists**, opt-ins are not subscribed to anything. Choose a list on every store, and repeat the **Marketing opt-in** setting on every store — both are per store.
</Note>

## What Gets Subscribed

| Customer at checkout | Result in Klaviyo |
| - | - |
| Ticks the box, gives an email | Profile subscribed to the list for **email** |
| Ticks the box, gives an email and a valid mobile number | Profile subscribed for **email and SMS**; phone number saved on the profile |
| Ticks the box, gives an email and an invalid or landline-formatted number | Subscribed for email only |
| Leaves the box unticked | Profile created or updated with the order, **not** subscribed |
| No email address | Nothing sent to Klaviyo |

The phone number is converted to international format (E.164, e.g. `+447700900123`) using the store's country before it is sent. A number Klaviyo would reject is dropped rather than failing the whole subscription.

Subscription happens once per order, at the moment the order is placed. Changing the list later only affects orders placed after you save.

## Single or Double Opt-In

Whether subscribers receive a confirmation email before they are marked subscribed is a setting on the list in Klaviyo, not in storekit. With double opt-in, the customer appears in Klaviyo straight away but stays unconfirmed until they click the link.

## Unsubscribes

Unsubscribes are handled entirely in Klaviyo; storekit never unsubscribes or suppresses a profile. A customer who unsubscribes and later places another order with the box ticked is sent as a new subscription request, which Klaviyo handles according to its own consent rules.

## Related

<CardGroup cols={2}>
  <Card title="Customer Profile Fields" icon="user" href="/docs/guides/integrations/marketing/klaviyo/event-reference#customer-profile">
    What storekit writes to the profile
  </Card>

  <Card title="Troubleshooting" icon="wrench" href="/docs/guides/integrations/marketing/klaviyo/troubleshooting">
    Customers tick the box but are not subscribed
  </Card>
</CardGroup>


## Related topics

- [Troubleshooting Klaviyo](/docs/guides/integrations/marketing/klaviyo/troubleshooting.md)
- [Customer Data](/docs/guides/marketing/customer-data.md)
- [Klaviyo](/docs/guides/integrations/marketing/klaviyo/overview.md)
- [Software & Subscription Invoices](/docs/guides/account/software-invoices.md)
- [Connecting Klaviyo](/docs/guides/integrations/marketing/klaviyo/connect.md)


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