Key Takeaways
- Free SMS server troubleshooting starts with 300 SMS lifetime · 300 contacts · 1 device max — then phone power, RF, and prepaid.
- Sends pause at the platform SMS lifetime cap. That is not a radio bug.
- 1 device means no hot spare — Doze looks like an outage.
- Operator airtime is separate. Free never means free carrier SMS.
- No Unlimited SMS titles. Upgrade when canaries are done.
Free SMS server troubleshooting — in-depth separates platform ceilings from handset reality. Limits that force upgrade · Pre-launch checklist. Docs: Developer Center.
300 SMS lifetime · 300 contacts · 1 device max. Pricing.
Spinning on Free? Check the lifetime SMS counter before you reinstall the APK.
Triage: platform vs radio
Panel says allowance exhausted → upgrade path. Panel says accepted but phone last-seen is stale → handset ops. Mixing those wastes a day.
Free is a canary lane. If production OTP needs a spare phone, you already left Free’s design envelope.
Symptom → fix table
| Symptom | Likely cause | Fix |
|---|---|---|
| 4xx / pause at send | Lifetime SMS exhausted | On Free and Developer, sending pauses when you use the plan SMS allowance rather than silently billing aggregator-style overage. Upgrade or request a custom allowance to continue. |
| Cannot add device 2 | Free device cap | Upgrade; Free max 1 |
| Contact import fails | 300 contacts | Trim list or upgrade |
| Accept, no bubble | Doze / RF / prepaid | Overnight uptime |
| 401 | Bad/rotated key | Fix env — never paste Bearer in chat |
| Duplicate OTP | Retry without Idempotency-Key | Idempotent send |
Allowance exhausted
300 SMS lifetime is total, not monthly. Burn it on staff canaries, then move to a paid device/volume plan.
Single-device failure modes
One phone = single point of failure. No failover column on Free. Multi-device.
Contact ceiling
300 contacts is enough to test import — not a blast CRM. Honor STOP anyway.
Next steps
Reproduce once on a staff MSISDN; screenshot last-seen + lifetime counter; then fix the matching row. Downloads · OTP.
Related product pages
Jump to the live product docs for this topic—not another long-form article.
- device and SMS volume pricingPlans and allowances
- Android SMS gateway product guideDefinition, product, and how to buy
- SMS API documentationLive endpoint reference
- download the Android gateway appGet the APK
