When someone signs up for a membership card and ticks the marketing box, Stokk pushes them to your own marketing platform as a subscribed profile (email and SMS) with their store and customer number attached for segmentation. No more CSV exports, and the consent is captured and stored as proof.
Go to Admin → Integrations → Marketing list. Pick your provider, Klaviyo or Mailchimp, paste the API key, and enter the list / audience ID new members should join. Hit Test connection to confirm. The key is encrypted at rest. Klaviyo syncs email + SMS; Mailchimp syncs email (SMS consent is still recorded in Stokk).
For Iceland we recommend setting that Klaviyo list to double opt-in; Klaviyo then sends its own confirmation, which is the cleanest consent posture.
Every membership sign-up has an unticked marketing box. The card never depends on it. Write your own wording on the membership card (Wallet cards → Membership cards → Edit → Marketing yes, in your words); Stokk stores the exact words shown, and when, as proof. Members can withdraw it on their card's page.
On a sign-up with a yes, the profile is pushed immediately; a 5-minute background sync retries anything that didn't go through.