To build a lasting relationship with your customers and comply with international regulations (GDPR), you must get explicit consent (or "opt-in") before sending marketing messages on WhatsApp.
The most natural and effective way to collect this consent is to add a checkbox directly on your Shopify checkout page.
By default, Shopify lets customers enter a phone number to receive order-related notifications (transactional notifications). However, having that number does not legally give you the right to send them promotional campaigns.
Enabling the marketing checkbox is an essential step to:
Comply with the law: Consent must be freely given, specific, and informed.
Protect your Meta score: Messaging customers who never asked for it leads to massive blocks, which hurts the health of your WhatsApp account.
Improve your ROI: You only reach out to customers who are genuinely interested in your offers.
Adding this checkbox takes a few clicks from your Shopify admin. No code needed.
Open the settings: From your Shopify admin, click Settings at the bottom left of the screen.
Checkout section: In the side menu, click the Checkout section.
Marketing consent: Scroll down until you find the part titled "Marketing consent".
Check the SMS option: Check the SMS marketing box.
Pre-selection (Optional): Shopify sometimes offers to pre-check the box by default. Warning: Depending on your jurisdiction (especially in Europe with GDPR), the box often has to stay unchecked by default for the consent to be valid.
Save: Click the Save button at the top right of the page.
By default, Shopify uses generic wording that mentions "SMS". To maximize your opt-in rate on Kanal, we recommend customizing this text to explicitly mention WhatsApp.
Go to Settings > Checkout.
Click the Manage checkout language button (usually at the bottom of the section or via the "Actions" button).
Look for the field matching SMS marketing (use the search bar and type "SMS").
Replace or complete the text. Example: "Sign me up to receive exclusive offers and order tracking via WhatsApp."
Once this option is enabled in Shopify, there is nothing more to do in Kanal:
Automatic detection: Kanal syncs each Shopify customer's opt-in status in real time.
Safe sending: When you run campaigns, Kanal automatically filters your contacts. If a customer did not check the box at checkout, they will not receive your marketing campaign, protecting you from any risk of being reported.
Dynamic status: If a customer unsubscribes later with the "STOP" keyword, Kanal updates the information and can even push it back to Shopify depending on your settings.
Checkout is the highest-quality collection point. A customer who agrees to receive your messages at the very moment they spend money on your store is an extremely receptive customer. Make sure your first message after the purchase lives up to that trust (usage tips, personalized thank-yous, etc.).
