Key Takeaways
- Multi-device failover overview: a second paired Android that can take the queue when the primary is offline, unpaired, or radio-dead — not round-robin chaos.
- Plans meter devices: Free 1, Starter 2, Professional 5, Business 15. Buy the slot before the incident.
- OTP spare must be allowed to send login codes. A promo phone is the wrong fail-over target.
- Dual SIM in one chassis is operator diversity, not a second heartbeat.
- Priced by devices and SMS send volume. You use your own phone and operator SMS credit. The spare still needs operator credit.
- Rehearse in daylight. An unpaired “spare” is inventory.
Search android sms gateway multi device failover overview after the first overnight “device offline” page. Product: dual SIM and multi-device. How-to depth: rotate devices for volume. This page is the HA picture: spare, triggers, drills.
Priced by devices and SMS send volume. You use your own phone and operator SMS credit.
Failover is a charged, paired, staff-canaried handset with permission to send the same class of traffic. A second phone in bubble wrap is a hobby.
What failover is (and is not)
Is: primary radio gone → jobs continue on another paired device you already trust. Is not: dual-SIM slot flip as a substitute for a second heartbeat; is not raising OEM SMS ceilings on one phone; is not DNS.
Warm spare vs a phone in a drawer
Warm means: charger, Wi-Fi, pairing live, battery exemptions, notification access if you use inbound, SIM that can send, staff OTP succeeded this month. Drawer fossils fail at 03:12. Keep-alive: app guide.
Trigger table: when traffic should move
| Signal | Move OTP? | Move promo? | Notes |
|---|---|---|---|
| Panel offline past heartbeat budget | Yes | Yes (or pause promo) | Physical check in parallel |
| Online, no SENT | After stock SMS test fails or radio confirmed dead | Pause first | Do not fail over into a barred SIM blindly |
| SENT, DLR pending storm | Canary first | Slow/stop | May be operator, not chassis |
| OEM killed process after update | Yes if spare healthier | Yes | Fix exemptions on primary later |
| Airtime zero | Yes if spare funded | Pause | Top-up is not failover |
Write this into the runbook— nicknames, not “the other phone.”
OTP failover is a named decision
The spare’s MSISDN may be new to users (codes still work). Some products pin “from” identity; here the SIM is the identity. If login SMS must stay on one number, failover is “same number on a spare chassis” (SIM swap — slow) or you accept a second originator. Decide before production.
Dual SIM is not two devices
Two operators, one battery, one OEM killer. Useful. Not HA. Plan device count is handsets.
How jobs find the living radio
Omit device targeting for primary; pass ids when you pin. On incident, pin OTP to the spare’s id. Do not leave retired phones paired. Live parameter names: Developer Center.
Daylight drill or it is fiction
Once a month: move a staff OTP to the spare, watch DLR, move back. If it takes more than fifteen minutes, the overview lied.
Cost of a second radio vs a 3 a.m. outage
Priced by devices and SMS send volume. You use your own phone and operator SMS credit. Starter’s 2 device cap is the first HA conversation. Free is 1 device / 300 SMS lifetime — enough to learn, not to fail over. A used handset plus a month of incidents avoided is the ROI.
Checklist
- Spare paired, charged, exempted, canary this month.
- OTP spare ≠ promo chassis unless you explicitly accept that risk.
- Triggers written; on-call can follow them.
- Retired devices unpaired.
- Plan device cap fits primary + spare (+ promo).
- Airtime on both SIMs.
- SIM-swap vs second-MSISDN policy for OTP documented.
- Drill date on the runbook.
- Notification access / default SMS app set on the spare too.
- No claim that dual SIM equals failover.
Next steps
Configure multi-device, size slots on pricing, and keep both agents alive via the app guide. HA is furniture. Assemble it before the outage.
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
- SMS API documentationLive endpoint reference
- device and SMS volume pricingPlans and allowances
- Android SMS gateway product guideDefinition, product, and how to buy
