SMS Notifications — Opt-in & Consent
Subi collects explicit SMS consent from subscription customers through three touchpoints. Every opt-in is recorded with a full audit trail (phone number, source, timestamp) so transactional SMS delivery is Twilio- and TCPA-compliant. Subi also counts the SMS marketing consent a customer already gave your store in Shopify, so those subscribers get your subscription texts without opting in again.
How customers opt in
1. Thank-you page (after checkout)
After completing a subscription order, customers see an SMS block with their phone pre-filled (or a country-code + number input if the phone is missing). Clicking Subscribe to SMS Updates creates the consent and triggers a welcome SMS.
2. Customer portal (subscription management)
An SMS section inside the Customer card. If a phone is on file, customers toggle it on. If not, they see an Add phone to subscribe button that opens the contact-info modal; once the phone is saved, the section transitions to a toggle without a page reload.
3. Shopify Customer Account extension
Same toggle UX embedded natively inside Shopify's Customer Account. Customers on stores using Shopify's new account surface get the opt-in flow without leaving Shopify.
Customers who agreed to SMS marketing in Shopify
Do customers who already agreed to SMS from your store in Shopify have to opt in again in Subi? No. If a customer's SMS marketing status in Shopify is Subscribed, Subi counts that as consent and sends them the subscription texts you turned on. Subi checks the customer's current Shopify status each time it sends, so a change in Shopify takes effect on the next text.
Which number gets the text: if the customer also opted in through Subi, the text goes to that number. Otherwise it goes to their phone number in Shopify.
What they see: the toggle is on in the customer portal and in Shopify Customer Account. On the thank-you page they see You're already subscribed to SMS updates instead of the sign-up form.
Other Shopify statuses: a customer whose Shopify status is anything other than Subscribed (for example Not subscribed or Unsubscribed) gets no texts until they opt in.
How customers opt out
In-app toggle: toggle OFF from the portal or Customer Account extension. This stops Subi's texts. For a customer counted through Shopify, it does not change their SMS marketing status in Shopify.
Unsubscribed in Shopify: if you or the customer turn off SMS marketing for them in Shopify, Subi stops texting them too, unless they also opted in through Subi.
Reply STOP — customers can reply STOP to any SMS. Consent is revoked immediately; the customer phone on file is preserved so email and order flows continue unaffected.
Merchant visibility
In the admin, the single subscription contract page shows a read-only SMS consent status line: Opted-in / Opted-out / Never opted-in, plus the source (thank you page / portal / customer account / Shopify) and timestamp. A customer counted through Shopify shows Opted in via Shopify, with the date Shopify recorded their consent when Shopify has one. No merchant action is required — customers drive opt-in and opt-out themselves.
Requirements
Subi Plus plan with SMS enabled.
At least one contract-SMS notification template enabled under Settings → Notifications → SMS.
Shopify store with subscription contracts.
Common support questions
"I opted out but I still got an SMS — why?" — Opt-out is immediate on new messages, but a message already enqueued before the opt-out can still be delivered. If your customer receives one more than a minute after opting out, contact support.
"Can I change my phone number after opting in?" — Yes, edit your phone in the Contact Info section of the portal or in Shopify Customer Account. Your existing consent carries over, so there's no need to opt in again. One exception: if your consent came from Shopify and you change your phone number in Shopify, Shopify resets your SMS marketing status, so you need to opt in again to keep receiving texts.
"Does replying STOP also cancel my subscription?" — No. STOP only opts you out of SMS updates. Your subscription is unchanged; you'll still receive email and order notifications.