Automated Calls

Automated calls (also known as robocalls or voice broadcasts) are outbound calls initiated programmatically without a live agent on the line. When the recipient answers, they hear a pre-recorded message or interact with an IVR flow. Automated calls are used for appointment reminders, payment notifications, surveys, alerts, and marketing messages.

How Automated Calls Work

Your application triggers a call via API
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Exotel calls the customer
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Customer answers
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Pre-recorded message plays (or IVR flow starts)
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Customer interacts (presses keys) or listens
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Call ends → Status callback sent to your server

Unlike agent-assisted calls, automated calls do not involve a human agent. The entire interaction is handled by the call flow.

Common Use Cases

Use Case	Description	Example Message
Appointment reminders	Remind customers of upcoming appointments	"Your appointment is tomorrow at 3 PM. Press 1 to confirm, 2 to reschedule."
Payment reminders	Notify about due or overdue payments	"Your payment of Rs. 500 is due on January 20. Press 1 for payment options."
Order updates	Inform about order status changes	"Your order #1234 has been shipped and will arrive by January 22."
Delivery notifications	Alert about upcoming deliveries	"Your delivery is scheduled between 2-4 PM today. Press 1 if someone will be available."
OTP / Verification	Deliver one-time passwords via voice	"Your verification code is 4-5-7-8. Repeating: 4-5-7-8."
Surveys	Collect customer feedback via DTMF	"How would you rate your experience? Press 1 for excellent, 2 for good, 3 for poor."
Emergency alerts	Broadcast urgent notifications	"Severe weather alert for your area. Stay indoors and follow safety guidelines."
Marketing promotions	Promote offers to opted-in customers	"Exclusive offer: 30% off on all electronics this weekend. Press 1 for details."
Event reminders	Remind about upcoming events	"Reminder: The webinar starts in 1 hour. Join at example.com/webinar."

Setting Up Automated Calls

Method 1: Single Automated Call (API)

Use the Connect to Flow API to call a single number and connect them to an IVR flow:

curl -u '<api_key>:<api_token>' -X POST 'https://api.exotel.com/v1/Accounts/<account_sid>/Calls/connect.json' \
  -d 'From=<customer_number>' \
  -d 'CallerId=<exophone>' \
  -d 'Url=http://my.exotel.com/exoml/start/<app_id>' \
  -d 'StatusCallback=https://your-app.com/call-status'

Parameters:

Parameter	Required	Description
From	Yes	Customer's phone number
CallerId	Yes	ExoPhone to display as caller ID
Url	Yes	The call flow (App) URL to execute when the customer answers
StatusCallback	No	URL to receive call completion details
TimeLimit	No	Maximum call duration in seconds
TimeOut	No	Time in seconds to ring the called party before treating the call as unanswered. The timer runs only during ringing and stops once the call is answered.

Method 2: Bulk Automated Calls (Campaign)

For calling large lists, use the Campaigns API:

curl -u '<api_key>:<api_token>' -X POST 'https://api.exotel.com/v1/Accounts/<account_sid>/Campaigns' \
  -H 'Content-Type: application/json' \
  -d '{
    "name": "Appointment_Reminders_Jan20",
    "caller_id": "<exophone>",
    "call_flow_id": "<flow_id>",
    "type": "automated",
    "numbers": [
      "+919876543210",
      "+919876543211",
      "+919876543212"
    ],
    "schedule": {
      "start_time": "2025-01-20T09:00:00+05:30",
      "end_time": "2025-01-20T18:00:00+05:30"
    },
    "retry": {
      "max_attempts": 2,
      "interval_minutes": 60
    },
    "concurrency": 10
  }'

See: Outbound Dialer for detailed campaign setup.

Method 3: Event-Triggered Automated Calls

Trigger automated calls from your application when specific events occur:

# Example: Trigger appointment reminder 24 hours before
def send_appointment_reminder(appointment):
    if appointment.datetime - now() <= timedelta(hours=24):
        exotel_api.connect_to_flow(
            from_number=appointment.customer_phone,
            caller_id=exophone,
            flow_url=f"http://my.exotel.com/exoml/start/{REMINDER_FLOW_ID}",
            status_callback="https://your-app.com/reminder-status"
        )

Common event triggers:

Event	Automated Call Action
Appointment created	Schedule reminder call 24 hours before
Payment overdue	Trigger payment reminder call
Order shipped	Call with delivery ETA
Account activity detected	Security alert call
Subscription expiring	Renewal reminder call

Designing Automated Call Flows

Informational Call (No Interaction)

A simple call that plays a message and hangs up:

Greeting ("Your order #1234 has been shipped. Expected delivery: January 22.")
    → Hangup

Interactive Call (With DTMF Input)

A call that collects caller input via keypress:

Greeting ("Your appointment is scheduled for tomorrow at 3 PM.")
    → IVR Menu ("Press 1 to confirm, Press 2 to reschedule, Press 3 to cancel.")
        → 1: Greeting ("Thank you for confirming.") → Hangup
        → 2: Greeting ("We will call you to reschedule.") → SMS (reschedule link) → Hangup
        → 3: Greeting ("Your appointment has been cancelled.") → Hangup

Survey Call

Collect structured feedback:

Greeting ("Thank you for being our customer. We would like your feedback.")
    → IVR Q1 ("How would you rate your experience? 1 for excellent, 2 for good, 3 for poor.")
        → IVR Q2 ("Would you recommend us? 1 for yes, 2 for no.")
            → Greeting ("Thank you for your feedback!") → Hangup

OTP Delivery Call

Deliver a verification code via voice:

Greeting ("Your verification code is 4. 5. 7. 8. Repeating: 4. 5. 7. 8.")
    → Hangup

tip

When delivering OTPs via voice, read each digit individually with a pause between them. Repeat the code at least once. This ensures the listener can note it down accurately.

Personalized Automated Calls

For personalized messages (e.g., including the customer's name, order number, or balance), use the Passthru applet to dynamically generate greetings:

Using Dynamic TTS

1. Add a Passthru applet at the start of the flow.
2. Your server returns personalized text.
3. A TTS Greeting applet reads the personalized message.

Passthru → Your server returns: "Hello Rahul, your balance is Rs. 1,500."
    → Greeting (TTS, dynamic text) → Hangup

Using Pre-Recorded Audio with Variables

1. Pre-record common message segments.
2. Use Passthru to determine which segments to play.
3. Chain multiple Greeting applets with the appropriate segments.

Greeting ("Your order") → Greeting (order number audio) → Greeting ("has been shipped") → Hangup

Handling Call Outcomes

Use Status Callbacks to track the outcome of each automated call:

Status	Meaning	Your Action
completed	Customer answered and heard the message	Mark as delivered
no-answer	Customer did not answer	Schedule retry (see Auto Retry)
busy	Customer's line was busy	Schedule retry
failed	Call could not be placed	Check number validity
canceled	Call was canceled before connection	Review campaign settings

Capturing IVR Responses

When the automated call includes an IVR, capture the customer's DTMF input via the Passthru applet or status callback:

# Status callback with IVR response
POST https://your-app.com/call-status
CallSid=<call_sid>&Status=completed&Digits=1&From=<customer_number>

Store the response in your database for follow-up actions:

def handle_reminder_response(request):
    digits = request.POST.get('Digits', '')
    customer = request.POST['From']

    if digits == '1':
        db.confirm_appointment(customer)
    elif digits == '2':
        db.flag_for_reschedule(customer)
    elif digits == '3':
        db.cancel_appointment(customer)

Scheduling Automated Calls

Scheduling Method	How It Works
Immediate	Call is placed as soon as the API request is made
Scheduled (campaign)	Campaign starts at a specified date/time
Event-triggered	Call is triggered by an application event (cron job, webhook, etc.)
Recurring	Set up a recurring schedule (daily, weekly) for regular reminders

Timing Best Practices

Time Window	Call Type	Notes
9:00 AM - 10:00 AM	Appointment reminders	Start of day, high attention
10:00 AM - 12:00 PM	Surveys, general notifications	Peak answer rates
2:00 PM - 4:00 PM	Payment reminders	Afternoon follow-ups
4:00 PM - 6:00 PM	Delivery confirmations	Before end of business
6:00 PM - 9:00 PM	Marketing, promotions	Evening availability (respect limits)

warning

Comply with TRAI regulations by restricting automated calls to 9 AM - 9 PM IST. Calls outside this window may result in penalties. Always filter out DND-registered numbers unless you have explicit prior consent.

Compliance for Automated Calls

Requirement	Details
TRAI calling hours	9:00 AM - 9:00 PM IST only
DND compliance	Must not call DND-registered numbers without consent
Consent	Obtain prior consent for promotional automated calls
Opt-out	Provide an option to opt out (e.g., "Press 9 to stop receiving these calls")
Caller ID	Must display a valid registered ExoPhone
Frequency limits	Avoid calling the same number more than 2-3 times per day

Adding an Opt-Out Option

Include an opt-out key in your IVR:

IVR ("Press 1 to confirm, Press 2 to reschedule, or Press 9 to stop receiving these calls.")
    → 9: Greeting ("You have been removed from our call list.") → Hangup
         → Webhook: remove customer from future campaigns

Monitoring and Analytics

Track automated call performance:

Metric	Description	Target
Delivery rate	Calls where the customer answered	Above 50%
Completion rate	Calls where the full message was heard	Above 40%
IVR response rate	Calls where the customer pressed a key	Above 30%
Action rate	Calls that resulted in the desired action	Depends on use case
Opt-out rate	Customers who opted out	Below 2%

See: Call Analytics

Best Practices

• Keep messages under 30 seconds -- Automated calls with long messages have high hang-up rates.
• Get to the point immediately -- State the purpose within the first 5 seconds.
• Always provide IVR options -- Let customers interact rather than just listen.
• Offer opt-out -- Include a way to stop receiving automated calls.
• Personalize when possible -- Include the customer's name or relevant details.
• Test before mass deployment -- Call yourself first to verify the message, audio quality, and IVR flow.
• Monitor and iterate -- Review delivery and response rates after each campaign and optimize.
• Combine with SMS -- For critical notifications, send an SMS as a backup in case the call is not answered.

Troubleshooting

Issue	Cause	Solution
Customer hears nothing	Flow has no Greeting applet	Add a Greeting as the first step
Call drops after greeting	No IVR or Hangup applet after greeting	Add the next applet in the flow
IVR responses not captured	Passthru or callback not configured	Set up a Passthru or status callback URL
Low answer rate	Unknown caller ID	Enable Truecaller Verification
Calls placed outside allowed hours	Schedule not configured	Set daily start/end times in campaign
Too many concurrent calls	Concurrency too high	Reduce concurrency setting

Related

• Outgoing Calls
• Outbound Dialer
• Auto Retry
• IVR Setup
• Greeting Message
• Campaigns API
• Voice v1 API -- Connect to Flow