Troubleshooting: phone numbers not syncing or missing consent
Before you troubleshoot
Phone numbers and SMS marketing consent usually go missing for one of two reasons:
- The customer never entered a phone number (nothing to sync).
- The customer entered a phone number, but did not give SMS marketing consent (you may have a phone, but no permission to market).
Quick diagnostic checklist (most common fixes)
- Phone (is it present?)
- SMS marketing / SMS subscription status (is it subscribed/consented?)
Issue: No phone number captured
If the phone number field wasn’t completed, there’s nothing to sync and no way to infer consent.
Common causes
- Phone number is optional at checkout and the customer skipped it.
- Accelerated checkout methods (e.g., Shop Pay / Apple Pay) may prefill or omit fields depending on the buyer’s saved info.
- Customer typed an incomplete number (missing country code or too few digits), which can fail validation in some systems.
What to do
+1 for the US/Canada). Consistent formatting reduces “missing phone” issues later.Issue: Phone number exists, but SMS consent is missing
This usually means the customer provided a phone number for order purposes but did not explicitly opt in to SMS marketing.
Most common reasons
- The customer didn’t check the SMS opt-in box at checkout.
- The opt-in box wasn’t shown for that checkout (due to checkout configuration, region requirements, or the specific checkout experience used).
- Consent was given through a different channel (e.g., a form or keyword), but you’re looking only at checkout-derived consent.
What to do
Understand the difference: transactional phone capture vs marketing opt-in
These two ideas are often confused:
- Transactional phone capture: a phone number collected to support order fulfillment (delivery updates, carrier questions, customer support).
- SMS marketing opt-in: explicit permission to receive promotional/marketing texts.
Your app may be able to use a phone number for certain transactional workflows, but marketing messaging workflows should only include contacts with SMS marketing consent.
Because the phone number field and SMS marketing consent are stored separately. A buyer can enter a phone number and still leave the marketing opt-in unchecked (or never see it, depending on checkout flow/settings). In that case, the phone exists, but marketing permission does not.
Checkout experience can vary based on factors like the buyer’s device, payment method, market/region requirements, and your Shopify checkout configuration. If this seems inconsistent, run controlled test checkouts using the same payment method and shipping destination as the affected orders.
Consent generally needs to be explicitly collected from the customer (for example, via checkout opt-in, a compliant form, or another opt-in method). Updating a phone number on a profile does not automatically create marketing consent.
Issue: You enabled opt-in, but new customers still don’t show up
If you’ve recently changed settings, give your next few test checkouts a careful review to confirm the flow end-to-end.
- A saved phone number
- An active SMS marketing subscription/consent