SMS channel
Twilio + Telnyx + Bandwidth A2P 10DLC with STOP keyword auto-DNC.
The SMS channel sends through an A2P 10DLC-registered number on Twilio, Telnyx or Bandwidth. Sequences are TCPA-gated before send, and inbound STOP keywords are detected automatically — the first opt-out adds that recipient to the DNC list across every channel, not only SMS.
- ·Twilio · Telnyx · Bandwidth A2P 10DLC support
- ·RFC 8058-style STOP / UNSUBSCRIBE keyword detection
- ·Auto-DNC across every channel on opt-out
- ·Per-number daily and hourly caps + quiet hours
- ·TCPA-compliant by default — never the operator’s job
- ·Two-way: replies land in Unibox alongside email
Why most cold SMS gets blocked at the carrier
Carriers in the US (10DLC) and India (TRAI DLT) expect business SMS senders and message bodies to be registered before they deliver them, and that registration is done with your provider, not in Autocloz. An opt-out that is not honoured straight away is a TCPA problem in the US.
- Delivery rate dropped below 60% on a number that worked yesterday
- STOP came in but the next outbound still went out (lawsuit risk)
- Carrier suspended the number with no warning
- TCPA complaint letter from a state AG
The detail.
10DLC is not optional — and we know it
Registering a 10DLC brand and campaign happens with your provider, and Autocloz does not check that registration before sending. What it does check is launch: a campaign with SMS steps and no active SMS sender is blocked, and one with no active SMS template in the workspace is warned.
STOP detection — a hard rule, not a heuristic
Every inbound SMS runs through detect_opt_out() with the carrier-recognised STOP keyword set. A match writes a DNC row immediately, tagged with the wildcard channel * so the next outbound outbound to that recipient — on email, LinkedIn, WhatsApp, or call — is also blocked.
Replies feel like a real conversation
Two-way SMS lands in the Unibox alongside email and WhatsApp, AI-tagged for intent, with the lead's full timeline one click away. Reply from the keyboard; the dispatcher honours the per-account cap.
Bring your own — or pick from the supported set.
The rules that keep your account alive.
Every rule below is enforced before any outbound action. The compliance gate either passes or it doesn’t dispatch.
- Block launch when SMS steps have no active SMS senderWhy: The pre-launch check stops a campaign whose SMS steps have no active sender, so the campaign never starts running.
- Cap every SMS sender per hour and per dayWhy: A new sender starts at 10 messages an hour and 50 a day; a capped sender is skipped for the next one, or the step waits.
- Auto-DNC on STOP / UNSUBSCRIBE / CANCEL / QUIT / END / OPTOUTWhy: These are carrier-recognised opt-out keywords; honouring all of them is required, not optional.
- Cross-channel DNC propagationWhy: If a recipient says STOP on SMS, they cannot legally be contacted on WhatsApp (same TCPA framework). Autocloz writes the wildcard '*' DNC row automatically.
- Quiet hours on every SMS sender, in the sender's timezoneWhy: New SMS senders get a night-time window read in the timezone saved on the sender, so set it to where your recipients are.
A real sequence using this channel — day by day.
- Day 0Email + SMS opener comboSMS arrives 30s after email open · 'just sent you a note' framing
- Day 2SMS reminderOnly if email_event.opened == false · short, value-first
- Day 5WhatsApp escalationIf still no reply · same template-gated rules apply
- Day 7Final SMS with breakup'Last note from me' framing; high reply rate
- Day 9Re-engage 30d laterAuto-snoozed; surfaces if any channel fires intent
A STOP from a prospect on any channel instantly suppresses them across all five — cross-channel DNC enforcement is built into the core, not bolted on.
Specific to this feature.
Do I need 10DLC registration to send SMS in the US?
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Yes — US carriers expect A2P SMS from a registered 10DLC brand and campaign. You register with Twilio, Telnyx or Bandwidth; Autocloz does not check that registration, so confirm it in the provider's console first.
What about India DLT?
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TRAI requires DLT registration of your entity, header and templates, done outside Autocloz. An MSG91 sender will not send without its DLT Sender ID and Flow ID; other providers are not checked.
Will replying STOP really opt the recipient out everywhere?
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Yes — STOP writes a DNC row with channel='*' (wildcard), so the next outbound on email, WhatsApp, call, or LinkedIn is also blocked. This is the legally safe default.
Can I send marketing SMS in India?
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Yes, through a DLT-registered entity and approved template. Autocloz applies no IST filter of its own: quiet hours use the sender's timezone, so set Asia/Kolkata on senders texting India.
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