Chile SMS Best Practices, Compliance, and Features

Chile SMS Market Overview

Market Conditions: Chile has a mature mobile market with high smartphone penetration and widespread SMS usage. The country's main mobile operators include Movistar, Entel, and WOM. While OTT messaging apps like WhatsApp are popular for personal communication, SMS remains crucial for business communications, particularly for authentication, notifications, and marketing purposes. Android devices dominate the market, though iOS has a significant presence in urban areas.

Key SMS Features and Capabilities in Chile

Chile offers comprehensive SMS capabilities including two-way messaging, concatenated messages, and number portability, though MMS is handled through SMS conversion with URL links.

Two-way SMS Support

Two-way SMS is fully supported in Chile, allowing businesses to engage in interactive messaging with customers. There are no specific restrictions on two-way messaging, making it ideal for customer service and engagement scenarios.

Concatenated Messages (Segmented SMS)

Support: Yes, concatenation is supported across most sender ID types, though some limitations exist for domestic long codes.
Message length rules: Standard SMS messages are limited to 160 characters (GSM-7) or 70 characters (UCS-2) before splitting occurs.
Encoding considerations: Both GSM-7 and UCS-2 encoding are supported, with UCS-2 required for messages containing special characters or non-Latin alphabets.

MMS Support

MMS messages are automatically converted to SMS with an embedded URL link to the media content. This ensures compatibility across all devices while maintaining the ability to share rich media content. Best practice is to use short URLs and include clear context in the message text.

Recipient Phone Number Compatibility

Number Portability

Number portability is available in Chile, allowing users to keep their phone numbers when switching carriers. This feature doesn't significantly impact message delivery or routing as the system automatically handles carrier identification.

Sending SMS to Landlines

Sending SMS to landline numbers is not supported in Chile. Attempts to send messages to landline numbers will result in a failed delivery with a 400 response error (code 21614). These messages won't appear in logs and won't incur charges.

Compliance and Regulatory Guidelines for SMS in Chile

Chile has recently strengthened its data protection framework with the new Data Protection Act (DPA), which aligns with international privacy standards. The Subsecretaría de Telecomunicaciones (SUBTEL) oversees telecommunications regulations, while the Personal Data Protection Agency enforces data privacy compliance.

Consent and Opt-In

Explicit Consent Requirements:

• Written or verifiable electronic consent must be obtained before sending marketing messages
• Consent records must be maintained and easily accessible
• Purpose of messaging must be clearly stated during opt-in
• Double opt-in is recommended for marketing campaigns

Best Practices for Documentation:

• Store consent timestamps and methods
• Maintain detailed records of opt-in sources
• Keep proof of consent for at least 2 years
• Include clear privacy policy references in opt-in flows

HELP/STOP and Other Commands

• STOP, PARA, and NO must be supported in Spanish
• AYUDA (HELP) command must provide support information
• Keywords must be case-insensitive
• Response to opt-out commands must be immediate and in Spanish
• Confirmation messages should be sent for both HELP and STOP requests

Do Not Call / Do Not Disturb Registries

While Chile doesn't maintain a centralized Do Not Call registry, businesses must:

• Maintain their own suppression lists
• Honor opt-out requests within 24 hours
• Keep records of opted-out numbers for at least 5 years
• Implement proactive filtering systems to prevent messaging to opted-out numbers

Time Zone Sensitivity

Chile observes specific time zones and seasonal changes:

• Recommended sending hours: 9:00 AM to 9:00 PM local time
• Time zone: Chile Continental (CLT/CLST)
• Exception: Emergency or security-related messages
• Best practice: Schedule messages between 10:00 AM and 8:00 PM for optimal engagement

Phone Numbers Options and SMS Sender Types in Chile

Alphanumeric Sender ID

Operator network capability: Not supported by Chilean operators Registration requirements: N/A Sender ID preservation: Alphanumeric IDs are overwritten with random long codes for delivery

Long Codes

Domestic vs. International:

• Domestic: Fully supported with direct carrier connections
• International: Supported but may be converted to local numbers

Sender ID preservation:

• Domestic: Yes, original sender ID maintained
• International: No, converted to local numbers

Provisioning time:

• Domestic: 1-2 business days
• International: Immediate availability

Use cases:

• Transactional messages
• Customer service
• Two-factor authentication
• Restrictions: No marketing messages allowed over domestic long codes

Short Codes

Support: Available through direct carrier arrangements Provisioning time: 8-12 weeks for approval and setup Use cases:

• High-volume marketing campaigns
• Premium messaging services
• Brand-focused communications

Restricted SMS Content, Industries, and Use Cases

Restricted Industries:

• Gambling and betting services
• Adult content
• Cryptocurrency promotions
• Political campaigns without proper authorization
• Unauthorized financial services

Regulated Industries:

• Banking (requires additional verification)
• Healthcare (subject to data protection requirements)
• Insurance (must include disclaimer information)

Content Filtering

Known Carrier Filters:

• URLs from unknown domains
• Multiple exclamation marks
• ALL CAPS messages
• High-frequency identical messages

Best Practices:

• Use registered URL shorteners
• Avoid excessive punctuation
• Maintain consistent sending patterns
• Include clear company identification

Best Practices for Sending SMS in Chile

Messaging Strategy

• Keep messages under 160 characters when possible
• Include clear call-to-actions
• Use personalization tokens thoughtfully
• Maintain consistent brand voice

Sending Frequency and Timing

• Limit to 4-5 messages per month per recipient
• Respect Chilean holidays and observances
• Avoid weekends unless specifically requested
• Space out messages to prevent fatigue

Localization

• Primary language: Spanish (Chilean dialect)
• Consider bilingual messages for international businesses
• Use local date and time formats
• Adapt content for cultural relevance

Opt-Out Management

• Process opt-outs within 24 hours
• Send confirmation of opt-out
• Maintain centralized opt-out database
• Regular audit of opt-out lists

Testing and Monitoring

• Test across major carriers (Movistar, Entel, WOM)
• Monitor delivery rates by carrier
• Track engagement metrics
• Regular A/B testing of message content

SMS API Integrations for Chile

Twilio

Twilio provides a robust REST API for sending SMS messages to Chile. Authentication uses your Account SID and Auth Token.

import * as Twilio from 'twilio';

// Initialize client with environment variables
const client = new Twilio(
  process.env.TWILIO_ACCOUNT_SID,
  process.env.TWILIO_AUTH_TOKEN
);

// Function to validate Chilean phone numbers
const validateChileanNumber = (phone: string): boolean => {
  // Chilean numbers: +56 9 XXXX XXXX
  return /^\+56[9][0-9]{8}$/.test(phone);
};

async function sendSMSToChile(
  to: string,
  message: string
): Promise<void> {
  try {
    if (!validateChileanNumber(to)) {
      throw new Error('Invalid Chilean phone number format');
    }

    const response = await client.messages.create({
      body: message,
      to: to,
      from: process.env.TWILIO_PHONE_NUMBER,
      // Optional: statusCallback URL for delivery updates
      statusCallback: 'https://your-callback-url.com/status'
    });

    console.log(`Message sent successfully: ${response.sid}`);
  } catch (error) {
    console.error('Error sending message:', error);
    throw error;
  }
}

Sinch

Sinch offers a straightforward API for SMS integration with built-in support for Chilean carriers.

import { SinchClient } from '@sinch/sdk-core';

class ChileSMSService {
  private client: SinchClient;

  constructor() {
    this.client = new SinchClient({
      projectId: process.env.SINCH_PROJECT_ID,
      keyId: process.env.SINCH_KEY_ID,
      keySecret: process.env.SINCH_KEY_SECRET
    });
  }

  async sendMessage(
    phoneNumber: string,
    message: string
  ): Promise<void> {
    try {
      const response = await this.client.sms.batches.send({
        sendSMSRequestBody: {
          to: [phoneNumber],
          from: process.env.SINCH_SENDER_ID,
          body: message,
          // Chile-specific delivery report
          deliveryReport: 'summary'
        }
      });

      console.log('Message batch ID:', response.id);
    } catch (error) {
      console.error('Sinch SMS error:', error);
      throw error;
    }
  }
}

MessageBird

MessageBird provides a comprehensive API with specific features for the Chilean market.

import { MessageBird } from 'messagebird';

class ChileMessageService {
  private client: MessageBird;

  constructor() {
    this.client = new MessageBird(process.env.MESSAGEBIRD_API_KEY);
  }

  async sendSMS(
    recipient: string,
    content: string
  ): Promise<void> {
    const params = {
      originator: process.env.MESSAGEBIRD_ORIGINATOR,
      recipients: [recipient],
      body: content,
      // Chile-specific parameters
      datacoding: 'auto',
      type: 'sms'
    };

    try {
      const response = await new Promise((resolve, reject) => {
        this.client.messages.create(params, (err, response) => {
          if (err) reject(err);
          resolve(response);
        });
      });

      console.log('MessageBird response:', response);
    } catch (error) {
      console.error('MessageBird error:', error);
      throw error;
    }
  }
}

Plivo

Plivo offers reliable SMS delivery to Chile with detailed delivery tracking.

import * as plivo from 'plivo';

class ChilePlivoService {
  private client: plivo.Client;

  constructor() {
    this.client = new plivo.Client(
      process.env.PLIVO_AUTH_ID,
      process.env.PLIVO_AUTH_TOKEN
    );
  }

  async sendSMS(
    destination: string,
    text: string
  ): Promise<void> {
    try {
      const response = await this.client.messages.create({
        src: process.env.PLIVO_SOURCE_NUMBER,
        dst: destination,
        text: text,
        // Chile-specific options
        url: 'https://your-callback-url.com/status',
        method: 'POST'
      });

      console.log('Message UUID:', response.messageUuid);
    } catch (error) {
      console.error('Plivo error:', error);
      throw error;
    }
  }
}

API Rate Limits and Throughput

• Standard Rate Limits:
  • 30 messages per second per long code
  • 100 messages per second per short code
  • Maximum of 1000 recipients per batch request

Throughput Management Strategies:

• Implement exponential backoff for retries
• Use message queuing systems (Redis, RabbitMQ)
• Batch messages in groups of 50-100
• Monitor delivery rates and adjust sending speed

Error Handling and Reporting

Logging Best Practices:

• Log all API responses and message IDs
• Track delivery status callbacks
• Monitor carrier-specific error codes
• Implement automated alerting for high failure rates

Troubleshooting Tips:

• Verify number formatting (+56 prefix)
• Check for content filtering triggers
• Monitor rate limit headers
• Maintain error code reference documentation

Recap and Additional Resources

Key Takeaways

1. Compliance First: Always obtain explicit consent and honor opt-outs
2. Technical Implementation: Use proper phone number formatting and handle rate limits
3. Content Guidelines: Follow Chilean Spanish language requirements and timing restrictions
4. Monitoring: Implement comprehensive logging and status tracking

Next Steps

1. Review Regulations

   • Consult SUBTEL guidelines (www.subtel.gob.cl)
   • Review Data Protection Act requirements
   • Check carrier-specific requirements

2. Legal Compliance

   • Engage local legal counsel for compliance review
   • Document consent collection processes
   • Establish privacy policy updates

3. Technical Setup

   • Choose appropriate SMS provider
   • Implement error handling and monitoring
   • Set up delivery tracking systems

Additional Resources

• Official Resources

  • SUBTEL Telecommunications Framework: www.subtel.gob.cl/marco-normativo
  • Chilean Data Protection Agency: www.dpachile.cl
  • National Consumer Service: www.sernac.cl

• Industry Guidelines

  • Mobile Marketing Association LATAM
  • Chilean Chamber of Digital Commerce
  • Local Telecommunications Industry Association