Few things tank customer experience faster than missing SMS. If reminders, confirmations, or replies aren't going out, work through this checklist in order.
Step 1 — Check the deliverability health banner
Go to Messages → Deliverability. If your delivery rate or failure rate is outside the healthy range (≥95% delivered, <5% failed), a warning banner appears listing the likely causes — including incomplete A2P 10DLC registration, invalid phone numbers in your customer list, or content getting flagged by carriers. Start here rather than hunting through settings.
If you're on the default (platform) messaging setup, 10DLC is registered under SalesThumb's shared account and there's nothing for you to fix on the registration side — a 10DLC-flagged banner in that case usually points at message content, not your account.
If you've connected your own Twilio account via Settings → Integrations → Bring Your Own Carrier, 10DLC registration lives with Twilio directly (you register your own brand/campaign in the Twilio Console). Check your campaign status there — if it isn't approved yet, that BYOC connection card also stays in "Pending verify" until Twilio confirms.
Step 2 — Confirm your sending setup is connected
On the default setup, SalesThumb's own number handles sending — there's no per-shop number to check. If you're on Bring Your Own Carrier, go to Settings → Integrations and check the status badge on your Twilio card: "Connected" means your credentials verified; "Pending verify" or "Not connected" means the SID/Auth Token/from-number pasted in aren't validating yet.
Step 3 — Confirm customer hasn't opted out
The single most common "missing SMS" reason: the customer replied STOP at some point. Customers page → click the customer → look for the "SMS opted out" badge (hover it to see which STOP keyword and date triggered it).
If it's there: they cannot receive marketing OR transactional SMS until they reply START. Email them and ask them to opt back in.
Step 4 — Confirm the customer's phone number is correct
Customers page → click the customer → verify phone number. Common issues:
- Missing area code (5551234567 vs (555) 123-4567)
- Wrong country code (we default to +1 US; if your customer's phone is Canadian, it should also be +1; international customers need their country code)
- Landline number — SMS won't deliver to landlines. Some carriers send a Text-to-Speech message; most just drop it.
Step 5 — Check the message template
If the customer's phone is right and they're not opted out, check the template that should be sending. Settings → Notifications → Message Templates.
Common issues: - Template is disabled (a manager turned off "appointment reminder" templates) - Template contains a merge field that this particular send doesn't supply, or one that isn't a real field at all (a typo, or `{{shop_address}}` when the real field is `{{address}}`) — SalesThumb doesn't block the send, it just sends with that field blank, so check the actual sent message for a blank-looking gap rather than assuming it was suppressed. The ten valid fields are listed on the Notifications page, and Configuring text reminders covers which ones each reminder actually fills in - Template exceeds 1,600 characters and splits across multiple segments; sometimes carriers drop multi-segment messages
Step 6 — Check the message status on the customer record
Open the customer's record and look at the Conversation card — it shows the full SMS + email history with that customer. A message tagged failed inline means the carrier or Twilio rejected it; hover or check the aggregate breakdown at Messages → Deliverability for the overall pattern (delivered / sent / queued / sending / failed / undelivered counts by Twilio status code) if it looks like more than one customer is affected.
Step 7 — Carrier-specific issues
Some patterns we see:
- T-Mobile filter on certain words — "free", "guaranteed", "click here", "$$$" can trigger filtering. Rewrite the template in plain language.
- Verizon strict on URLs — some Verizon prefixes block short-link URLs. Use full URLs (salesthumb.com/...) instead of bit.ly or short codes.
- Opt-out keywords — carriers treat STOP and its variants as case-insensitive, so a customer replying "stop" in lowercase is opted out just the same. Our templates print it uppercase for clarity, not because case matters.
When to escalate to support
If you've worked through all 7 steps and customers still aren't receiving SMS, contact info@roffik.com with:
- The customer name + phone
- The expected send time (e.g. "yesterday at 9 AM PT")
- The template name
- A screenshot of the customer's Conversation card (or the Messages → Deliverability breakdown if several customers are affected)
We can pull carrier-level logs and find the failure.