Guide · 5 min read

Android phones are a cheap way to send texts, but phones go offline: dead battery, no signal, a restart. When a message really must go out, Twilio can step in as the safety net — and you pay it only for the messages your phones couldn’t send.

Three ways to send

• Devices only — your phones send everything (the default; no per-message cost).
• Devices and Twilio — phones first. If every phone is offline, Twilio sends instead.
• Twilio only — everything goes through Twilio, no phone needed.

Pick one in SwarmSMS → Settings → Delivery (Pro and Agency plans).

Set it up

1. Create a Twilio account, copy the Account SID and Auth Token from the console and buy a number (or create a Messaging Service).
2. Paste them into Settings → Delivery with the number in international format, for example +61400111222.
3. Save and press Send a test via Twilio.
4. To receive replies to the Twilio number, set its A message comes in webhook to the URL shown on the settings page.

What happens when phones drop

• A new message goes straight to Twilio if no phone is online.
• Messages already waiting for a phone move to Twilio after a short wait (90 seconds by default, adjustable) if still no phone is online.
• If a phone fails a message and no other phone can retry it, Twilio gets it once.
• The moment any phone is back online, sending returns to the phones.

Delivery reports come back from Twilio automatically, so you see sent, delivered or failed (with Twilio’s error code) in your logs just like phone messages.

Compliance still applies

Opt-outs and consent are honoured on every channel. If someone replies STOP to your Twilio number, Twilio blocks further texts and SwarmSMS marks that contact unsubscribed everywhere. Twilio trial accounts only text verified numbers, and some countries (such as the US) require number registration before you can send marketing texts.

Costs

Twilio bills you per message plus number rental. With Devices and Twilio you pay it only for the messages your phones couldn’t send, which for most sites is very few.