Key Takeaways
- Scenario 1803 is dual-SIM routing for failed-delivery and return-to-sender SMS — not first-ETA RSSI, not border POD, not cold-chain ticks.
- “We missed you” should reuse the From the buyer already saw. A new number looks like a scam.
- NDA / reattempt keywords belong on that logistics MSISDN. Promo STOP is a different list.
- Priced by devices and SMS send volume. You use your own phone and operator SMS credit. Free is 1 / 300 / 300.
- Courier app OTP stays on a hub phone that never carries exception volume.
- Developer Center owns slot addressing. The TMS owns the exception id.
Summary
Scenario 1803 is logistics dual-SIM for failed delivery and RTS. The TMS owns the exception. The depot Android still has to text a reattempt window when one operator is congested. Priced by devices and SMS send volume. You use your own phone and operator SMS credit.
A “we missed you” from a number the buyer has never seen will be treated as phishing — and you still spent the airtime.
Failed delivery and RTS
One SMS per exception state (missed, carded, RTS), not per GPS ping. Dual SIM · logistics architecture. Slots: Developer Center. Industry radio: GSMA.
Slot map
| Message | From rule | Fallback | Never |
|---|---|---|---|
| We missed you / reattempt | Same as first ETA | Other tray, same MSISDN if possible | New number to “save” roaming |
| RTS / collect at depot | Same thread | Voice runbook | Promo copy in the same body |
| Courier OTP | Hub-only phone | CPaaS if no phone ops | Tray 2 on the exception unit |
Keep the exception thread
After reboot, re-resolve MSISDN — slot indexes drift. DLR · Doze. Inbound “LEAVE / DEPOT” must hit a named inbox. Two-way.
Cost
Priced by devices and SMS send volume. You use your own phone and operator SMS credit. Free: 1 device, 300 SMS lifetime, 300 contacts. Developer: 25,000 SMS/year. Paid plans uncap platform volume; devices still meter. Pricing.
Hub ops
Label trays. Spare before monsoon first-attempt fails. Failover · setup.
Security
Do not SMS full access codes plus address on a missed-delivery text. Trust Center. Parcel-locker promo needs STOP elsewhere. STOP.
Checklist
- Exception id idempotent.
- From matches first ETA.
- Post-reboot canary both trays.
- OTP on a different phone.
- LEAVE/DEPOT mapped; promo STOP separate.
Next steps
Transactional SMS · SMS API documentation.
Related product pages
Jump to the live product docs for this topic—not another long-form article.
- multi-device and dual SIM routingCapacity and failover
- transactional SMS for orders and alertsEvent-driven messages
- SMS delivery reports (DLR)Delivery status tracking
- SMS API documentationLive endpoint reference
