Trigger live voice calls from your IoT devices when sensor data meets a condition you define — a temperature spike, a tank level critical, a device offline. A ringing phone is the alert channel that's hardest to ignore, and unlike SMS or email, the recipient must actively answer or hang up.
To send voice-call alerts from Ubidots, create an event with a trigger condition (value-based, inactivity, geofence, or context-based) and add a Make voice call action. Ubidots dials the configured number(s) and reads your message aloud in the voice and language you choose.
When to use voice-call alerts for IoT
Emergencies that need human attention — equipment failures, safety incidents, environmental thresholds breached.
Night-shift and on-call rotations — a phone call wakes the operator; a Slack message doesn't.
Recipients without smartphones or stable data — voice reaches any phone with reception.
Escalation chains — first SMS, then voice if no acknowledgement.
Multi-language operations — Ubidots reads messages aloud in English, Spanish, French, German, Portuguese, and many more.
Requirements
An Ubidots account on the Industrial plan or higher.
One or more recipient phone numbers with country code.
Sufficient voice-call credit on your account (calls are billed per country and destination prefix — see the pricing schedule).
1. Create a new event
Go to the Data → Events section and click the + button at the top right. Choose the event type that matches your need: conditional, global, or scheduled.
Configure the trigger logic with AND/OR conditions. The trigger types are documented separately: value-based, inactivity, geofence, and context-based.
2. Configure the voice-call action
Once the trigger logic is set, click + add action and select Make voice call.
Recipients — add one or more phone numbers, each with country code. Multiple numbers will be dialed in sequence.
Active-trigger message — the text Ubidots will read aloud when the event fires. Use the tag icon at the top-right of the message field to insert dynamic placeholders: device name, variable name, current value, timestamp, and more.
Back-to-normal message (optional) — read when the trigger condition stops being met. See Back-to-Normal Events.
Voice — choose Alice (female) or John (male).
Language — English, Spanish, French, German, Portuguese, and many more.
Timestamp format — by default, timestamps render as
YYYY-MM-DD HH:mm:ss TZ. If you'd rather have UNIX epoch milliseconds spoken, double-click the timestamp tag and delete everything after the pipe (|) symbol.Repeat action (optional) — re-dial the recipient(s) up to 50 times while the event stays active.
Click Save.
3. Settings tab
Name the event, optionally add a description, apply tags for end-user visibility control, set a cooldown period (in seconds) to mute repeated firings, and define one or more active windows during which the event is allowed to run. Click Save.
Best practices
Keep messages short — voice calls typically last under a minute. Lead with the device name and the threshold breached, not preamble.
Match voice language to recipient — a Spanish operator will tune out an English-language reading.
Avoid abbreviations — say "degrees Celsius" rather than "°C"; "amps" rather than "A".
Combine with SMS — if the recipient misses the call, an SMS leaves a record. Add both actions to the same event.
Use repeat-action sparingly — calling someone every minute for an hour is a great way to get muted permanently. Set a sensible cooldown.
Pricing & limits
Per-call billing: billed by country and destination prefix — see the pricing schedule.
Call duration: typically under 1 minute.
Repeat-action limit: max 50 repetitions per event firing.
Plan availability: Industrial plan or higher.
Frequently asked questions
Why didn't the call go through?
Common causes: (1) the number is missing or has the wrong country code; (2) the destination is on a regional block list (some carriers block automated calls — try a different prefix); (3) the event is outside its active window; (4) the action is muted by the cooldown period; (5) account voice-call credit is exhausted.
What happens if the recipient doesn't pick up?
If the call goes to voicemail, Ubidots reads the message into the voicemail. The call counts as delivered for billing purposes. Use the repeat action to redial if you need confirmation.
Can I change the voice or language mid-message?
No — one voice and one language per action. To send the same alert in two languages, add two voice-call actions to the same event with different recipients.
Can I include sensor values in the spoken message?
Yes — use the tag icon at the top-right of the message field to insert dynamic placeholders. Ubidots reads them aloud as part of the message. Avoid units symbols (use "degrees" not "°") so the text-to-speech engine reads them correctly.
Voice vs. SMS — which should I use?
Voice for emergencies that need immediate human attention; SMS for confirmations and lower-urgency alerts. Many teams send both: a voice call to wake the operator, plus an SMS that leaves a written record. See Sending SMS Notifications for the SMS counterpart.