Key Takeaways
- Free SMS server on Android forces upgrade when you hit 1 device, 300 SMS lifetime, or 300 contacts — not when you want “Unlimited SMS.”
- Sends pause at the platform SMS allowance on Free (and Developer). No silent $0.0x overage.
- You still bring a phone and operator airtime. Free is a control-plane trial, not free carrier credit.
- Upgrade for more devices and volume — carrier fair-use still applies.
- 300 SMS lifetime · 300 contacts · 1 device max
Free SMS server on Android: limits that force upgrade is the honest ceiling list — not a promise of unmetered carrier send. Free pricing model · Pricing. Docs: Developer Center.
300 SMS lifetime · 300 contacts · 1 device max. You fund the SIM.
300 lifetime · then pause
When the bar fills, Free stops sending until you upgrade — it does not invent overage.
What Free actually caps
Platform device count, platform SMS volume (lifetime), and contacts. It does not cap your operator’s prepaid balance — that is a separate bill you already pay.
“Free SMS server” means a free control-plane lane to prove the path. It does not mean unlimited carrier SMS.
Limits that force upgrade
| Limit | Free value | Why you upgrade |
|---|---|---|
| Devices | 1 | Need spare phone / OTP isolation |
| SMS volume | 300 lifetime | Production OTP or alerts beyond canary |
| Contacts | 300 | Lists outgrow the trial address book |
| Allowance exhausted | Sends pause | 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. |
300 SMS lifetime — not monthly
Do not budget Free as a monthly refill. Burn the lifetime on staff canaries and DLR tests, then move to a paid device/volume plan.
One device ceiling
One handset means no hot spare. Overnight Doze on that single phone is an outage. Keep device online · Multi-device.
300 contacts
Enough to prove import and segments — not a bulk campaign CRM. Honor STOP even on Free.
Free software ≠ free carrier SMS
Operator segments still bill your SIM. Failed DLR after the radio fired is not a platform refund. OTP use case.
Next steps
Send ten staff SMS on Free; watch the lifetime counter; decide the paid device count before OTP launch. Downloads.
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
