Timor-Leste SMS Best Practices, Compliance, and Features

Sending SMS to Timor-Leste requires understanding ANC regulations, registering alphanumeric sender IDs with Telkomcel, and choosing the right SMS API provider. This guide covers everything you need to send compliant, reliable SMS messages to +670 numbers in Timor-Leste.

Timor-Leste SMS Market Overview

Market Conditions: Three mobile operators serve Timor-Leste: Telkomcel (Indonesian Telin/Telkom Indonesia International), Telemor (Vietnamese Viettel), and Timor Telecom. Together they provide 98% national coverage. Telemor holds the largest market share at 47% (2017 data), while Telkomcel positions itself as a leading telecommunications provider (March 2025). SMS remains the most reliable communication channel for reaching users across rural and urban regions, especially for business communications and authentication services. While OTT messaging apps grow in urban areas, SMS delivers consistent results nationwide.

SMS Features and Capabilities in Timor-Leste

Timor-Leste offers basic SMS functionality with key limitations. All customers must register Alphanumeric Sender IDs before sending SMS messages through Telkomcel Timor-Leste.

Does Timor-Leste Support Two-Way SMS?

Timor-Leste does not support two-way SMS. Send outbound messages only – you cannot receive replies through the same channel. For interactive communication, use alternative channels like OTT messaging apps in urban areas.

Concatenated Messages (Segmented SMS)

Support: Not supported in Timor-Leste. Keep messages within single-segment limits.

Message length rules: Standard 160 characters (GSM-7) or 70 characters (UCS-2). Longer messages will be truncated or rejected.

Encoding considerations: Use UCS-2 encoding for non-Latin characters (Tetum and Portuguese special characters).

MMS Support in Timor-Leste

Timor-Leste automatically converts MMS messages to SMS with an embedded URL link. This ensures delivery while letting you share multimedia content through linked resources. Host images and videos on a reliable CDN and use shortened URLs for optimal results.

Phone Number Compatibility

Number Portability

Timor-Leste does not offer number portability. Mobile numbers remain tied to their original carrier. This simplifies message routing but limits consumers' ability to switch carriers.

Can You Send SMS to Landlines in Timor-Leste?

Timor-Leste does not support SMS to landline numbers. Attempts to send to landlines return a 400 response with error code 21614. The message will not be delivered or charged.

Timor-Leste SMS Compliance Requirements (ANC Regulations)

The Autoridade Nacional de Comunicações (ANC) regulates SMS communications in Timor-Leste under Decree-Law No. 15/2012. The ANC oversees telecommunications, radio-communications, broadcasting (partially), and internet services. Register your service with the ANC and comply with their guidelines for message delivery and consumer protection.

ANC Contact: Ground floor, Telecom Building, Avenida Xavier do Amaral No. 8, Caicoli, Dili (tel: +670 3311415, email: info@anc.tl).

Consent and Opt-In Requirements

Explicit Consent Requirements:

• Obtain clear, documented opt-in consent before sending marketing messages
• Maintain detailed records of when and how you obtained consent
• Include terms of service and privacy policy information during opt-in
• Disclose message frequency and content type upfront

HELP/STOP and Other Commands

While Timor-Leste doesn't mandate HELP/STOP functionality, implement these features as best practice:

• Support standard STOP, CANCEL, UNSUBSCRIBE commands
• Include HELP functionality for user support
• Offer support in Tetum and Portuguese
• Acknowledge opt-out requests within 24 hours

Do Not Call / Do Not Disturb Registries

Timor-Leste does not maintain an official Do Not Call registry. Best practices:

• Maintain your own suppression lists
• Honor opt-out requests immediately
• Document all opt-out requests and actions
• Clean contact lists regularly to remove inactive numbers

Time Zone Sensitivity for SMS Campaigns

Timor-Leste observes TLT (Timor Leste Time, UTC+9) year-round with no daylight saving time (IANA identifier: Asia/Dili).

Message timing best practices:

• Send between 9:00 AM and 8:00 PM TLT
• Avoid religious observances and national holidays
• Reserve outside-hours messaging for urgent communications (authentication codes, critical alerts)

SMS Sender ID Types for Timor-Leste

Alphanumeric Sender ID Registration

Operator network capability: Supported by Telkomcel Timor Leste

Registration requirements: Pre-register your sender ID (approximately 2 weeks processing time)

Sender ID preservation: Yes – registered IDs appear as-is to recipients

Best practices: Choose a recognizable brand name, avoid generic terms, and keep it under 11 characters for optimal display across devices.

Long Codes

Domestic vs. International: International long codes supported; domestic not available

Sender ID preservation: Yes – the original sender ID is preserved

Provisioning time: Immediate for international long codes

Use cases: Transactional messages and two-factor authentication

Short Codes

Support: Not currently available in Timor-Leste

Provisioning time: N/A

Use cases: N/A

Restricted Content and Industries

Restricted Industries and Content:

• Gambling and betting services
• Adult content or services
• Unauthorized financial services
• Political campaign messages without proper authorization
• Cryptocurrency promotions

Content Filtering

Known Carrier Rules:

• Messages containing certain keywords may be blocked
• Use URLs from reputable domains
• Avoid excessive capitalization and special characters

Best Practices to Avoid Filtering:

• Use clear, professional language
• Avoid spam trigger words
• Include your company name in messages
• Keep URLs short and recognizable

Best Practices for Sending SMS in Timor-Leste

Messaging Strategy

• Keep messages under 160 characters when possible
• Include clear calls-to-action
• Maintain consistent sender ID across campaigns
• Personalize messages with recipient's name when appropriate

Sending Frequency and Timing

• Limit to 2–3 messages per week per recipient
• Respect local holidays and cultural events
• Schedule campaigns during business hours
• Space out bulk sends to prevent network congestion

Localization

• Primary languages: Tetum and Portuguese
• Consider English for business communications
• Use proper character encoding for local language support (UCS-2 for special characters)
• Respect cultural sensitivities in message content

Opt-Out Management

• Process opt-outs within 24 hours
• Maintain centralized opt-out database
• Include opt-out instructions in messages
• Conduct regular audits of opt-out compliance

Testing and Monitoring

• Test messages across different devices
• Monitor delivery rates by carrier
• Track engagement metrics (opens, clicks, conversions)
• Review bounce rates and invalid numbers regularly

SMS API Integrations for Timor-Leste

How to Send SMS to Timor-Leste with Twilio

Twilio provides a robust SMS API for sending messages to Timor-Leste. Authenticate using your Account SID and Auth Token.

import * as Twilio from 'twilio';

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

// Function to send SMS to Timor-Leste
async function sendSMSToTimorLeste(
  to: string,
  message: string,
  senderId: string
): Promise<void&gt; {
  try {
    // Ensure proper formatting for Timor-Leste numbers (+670)
    const formattedNumber = to.startsWith('+670') ? to : `+670${to}`;

    const response = await client.messages.create({
      body: message,
      from: senderId, // Must be pre-registered alphanumeric sender ID
      to: formattedNumber,
    });

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

How to Send SMS to Timor-Leste with Sinch

Sinch requires API Token authentication and supports both REST and SDK approaches.

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

// Initialize Sinch client
const sinchClient = new SinchClient({
  projectId: process.env.SINCH_PROJECT_ID,
  apiToken: process.env.SINCH_API_TOKEN
});

// Function to send SMS using Sinch
async function sendSinchSMS(
  to: string,
  message: string,
  senderId: string
): Promise<void&gt; {
  try {
    const response = await sinchClient.sms.batches.send({
      to: [to],
      from: senderId,
      body: message,
      delivery_report: 'summary' // Enable delivery reporting
    });

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

MessageBird SMS API for Timor-Leste

MessageBird offers a straightforward API for SMS delivery to Timor-Leste.

import messagebird from 'messagebird';

// Initialize MessageBird client
const mbClient = messagebird(process.env.MESSAGEBIRD_API_KEY);

// Function to send SMS via MessageBird
function sendMessageBirdSMS(
  to: string,
  message: string,
  senderId: string
): Promise<void&gt; {
  return new Promise((resolve, reject) =&gt; {
    mbClient.messages.create({
      originator: senderId,
      recipients: [to],
      body: message,
      datacoding: 'unicode' // Support for local language characters
    }, (err, response) =&gt; {
      if (err) {
        reject(err);
        return;
      }
      console.log('MessageBird response:', response);
      resolve();
    });
  });
}

Plivo SMS API for Timor-Leste

Plivo provides reliable API coverage for Timor-Leste.

import plivo from 'plivo';

// Initialize Plivo client
const plivoClient = new plivo.Client(
  process.env.PLIVO_AUTH_ID,
  process.env.PLIVO_AUTH_TOKEN
);

// Function to send SMS via Plivo
async function sendPlivoSMS(
  to: string,
  message: string,
  senderId: string
): Promise<void&gt; {
  try {
    const response = await plivoClient.messages.create({
      src: senderId,
      dst: to,
      text: message,
      url_strip_query_params: false // Preserve URL parameters in messages
    });

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

API Rate Limits and Throughput

• Default rate limit: 100 messages per second
• Batch processing: Recommended for volumes over 1,000/hour
• Retry logic: Implement exponential backoff

Throughput Management Strategies:

• Queue messages using Redis or similar technology
• Implement batch sending for large campaigns
• Monitor delivery rates and adjust sending speed accordingly

Error Handling and Reporting

// Common error handling utility
function handleSMSError(error: any): void {
  const errorTypes = {
    INVALID_NUMBER: 'Invalid phone number format',
    BLOCKED_NUMBER: 'Number is blocked',
    CARRIER_ERROR: 'Carrier delivery failed',
    RATE_LIMIT: 'Rate limit exceeded'
  };

  // Log error details
  console.error({
    timestamp: new Date().toISOString(),
    errorType: error.code,
    message: errorTypes[error.code] || 'Unknown error',
    details: error
  });

  // Implement retry logic for specific error types
  if (error.code === 'RATE_LIMIT') {
    // Add to retry queue
  }
}

Frequently Asked Questions (FAQ)

Does Timor-Leste support two-way SMS messaging?

No, Timor-Leste does not support two-way SMS. Send outbound messages only – you cannot receive replies through the same channel. For interactive communication, consider using alternative channels like OTT messaging apps in urban areas.

How long does alphanumeric sender ID registration take in Timor-Leste?

Alphanumeric sender ID registration in Timor-Leste takes approximately 2 weeks. Pre-register your sender ID with Telkomcel Timor Leste before sending SMS messages. Registered sender IDs appear as-is when delivering messages.

Which mobile operators provide SMS coverage in Timor-Leste?

Timor-Leste has three mobile operators: Telkomcel (Indonesian Telin/Telkom Indonesia International), Telemor (Vietnamese Viettel), and Timor Telecom. These operators jointly provide 98% national coverage. Telemor holds the largest market share at 47% (2017 data).

What timezone should I use when scheduling SMS campaigns for Timor-Leste?

Timor-Leste observes TLT (Timor Leste Time, UTC+9) year-round with no daylight saving time (IANA identifier: Asia/Dili). Send messages between 9:00 AM and 8:00 PM TLT. Reserve outside-hours messaging for urgent communications like authentication codes.

Can I send SMS messages to landline numbers in Timor-Leste?

No, Timor-Leste does not support SMS to landline numbers. Attempts to send to landlines return a 400 response with error code 21614. The message will not be delivered or charged.

Which regulatory authority oversees SMS communications in Timor-Leste?

The Autoridade Nacional de Comunicações (ANC) regulates SMS communications in Timor-Leste under Decree-Law No. 15/2012. All telecommunications service providers must register with the ANC and comply with their guidelines. Contact: Ground floor, Telecom Building, Avenida Xavier do Amaral No. 8, Caicoli, Dili (tel: +670 3311415, email: info@anc.tl).

Does Timor-Leste support concatenated SMS messages?

No, concatenated messaging is not supported in Timor-Leste. Standard SMS character limits apply: 160 characters (GSM-7) or 70 characters (UCS-2). UCS-2 encoding supports non-Latin characters like Tetum and Portuguese special characters.

Is mobile number portability available in Timor-Leste?

No, Timor-Leste does not offer number portability. Mobile numbers remain tied to their original carrier, which simplifies message routing but limits consumers' ability to switch operators while keeping the same phone number.

Key Takeaways for Sending SMS to Timor-Leste

Compliance Requirements

1. Sender ID Registration:

   • Pre-register alphanumeric sender IDs (2 weeks processing time)
   • Maintain opt-out lists and honor requests within 24 hours
   • Respect time zone restrictions (9:00 AM – 8:00 PM TLT)

2. Technical Considerations:

   • Implement proper error handling and retry logic
   • Use UCS-2 encoding for Tetum and Portuguese characters
   • Monitor delivery rates by carrier
   • Keep messages under 160 characters (no concatenation support)

3. Best Practices:

   • Test thoroughly before launching large campaigns
   • Maintain clean, updated contact lists
   • Document consent and opt-outs meticulously
   • Use professional, clear language to avoid content filtering

Next Steps

1. Review ANC regulations at http://anc.tl/legislation/
2. Consult with local legal counsel for compliance review
3. Set up test accounts with your preferred SMS provider
4. Implement monitoring and reporting systems for delivery tracking

Additional Resources

• Official Resources:

  • Autoridade Nacional de Comunicações: http://anc.tl/
  • Telecommunications Decree-Law: Decree-Law No. 15/2012

• Industry Guidelines:

  • GSMA Guidelines for Timor-Leste
  • Mobile Marketing Association Best Practices

Related SMS Guides

Looking to send SMS to other countries? Check our comprehensive guides:

• Indonesia SMS Guide - Neighboring market with similar regulations
• East Timor SMS Pricing - Detailed pricing information
• E.164 Phone Format Guide - International number formatting standards