Shopify lets merchants collect WhatsApp marketing opt-in at checkout. That signal must be distinguished from contact details needed for an order and consent given for other channels. Source officielle.
A practical check
Check the text shown to shoppers, evidence of their choice, the customer-record status, and the unsubscribe path. Test one checkout with opt-in and one without.
At checkout, a buyer accepts WhatsApp but declines email. The customer record should preserve two separate states. An email campaign must not borrow WhatsApp consent, or vice versa.
What the evidence supports
A phone number supplied for delivery is not by itself marketing permission. Review applicable rules before sending a campaign. Date the check and retain the source documentation so that later changes can be verified.