Guam SMS Best Practices, Compliance, and Features

Guam SMS Market Overview

Market Conditions: Guam's mobile market is dominated by major operators like DOCOMO PACIFIC and GTA. As a U.S. territory, Guam follows U.S. telecommunications standards and regulations. Mobile penetration is high, with widespread smartphone adoption and active usage of both traditional SMS and OTT messaging apps.

Key SMS Features and Capabilities in Guam

Guam supports standard SMS features with some limitations on two-way messaging and specific requirements for sender IDs, following U.S. telecommunications standards.

Two-way SMS Support

Two-way SMS is not supported in Guam through standard channels. Businesses looking to implement two-way messaging capabilities should consider alternative communication methods or specialized enterprise solutions.

Concatenated Messages (Segmented SMS)

Support: Yes, concatenated messaging is supported in Guam, though support may vary by sender ID type.
Message length rules: Standard SMS length limits apply - 160 characters for GSM-7 encoding, 70 characters for Unicode.
Encoding considerations: Both GSM-7 and UCS-2 encodings are supported, with messages automatically split and rejoined based on the encoding used.

MMS Support

MMS messages are automatically converted to SMS with an embedded URL link. This ensures compatibility across different device types while still allowing rich media content to be shared through clickable links.

Recipient Phone Number Compatibility

Number Portability

Number portability is not available in Guam. This means phone numbers remain tied to their original carriers, which can simplify message routing and delivery.

Sending SMS to Landlines

Sending SMS to landline numbers is not possible in Guam. Attempts to send messages to landline numbers will result in a 400 response with error code 21614, and no charges will be incurred.

Compliance and Regulatory Guidelines for SMS in Guam

As a U.S. territory, Guam follows federal telecommunications regulations, including the Telephone Consumer Protection Act (TCPA). Businesses must comply with both U.S. federal laws and local Guam telecommunications guidelines administered by the Guam Public Utilities Commission.

Consent and Opt-In

Explicit Consent Requirements:

• Obtain written consent before sending marketing messages
• Maintain clear records of how and when consent was obtained
• Include clear terms of service and privacy policy references
• Specify message frequency and content type in consent forms

HELP/STOP and Other Commands

• Required Keywords: All SMS programs must support standard STOP, CANCEL, END, QUIT, and HELP commands
• Response Time: Process opt-out requests within 24 hours
• Language Support: Commands must be recognized in both English and Chamorro
• Confirmation Messages: Send confirmation messages for both HELP and STOP requests

Do Not Call / Do Not Disturb Registries

• Guam follows the U.S. National Do Not Call Registry
• Best Practices:
  • Regularly scrub contact lists against the DNC registry
  • Maintain internal opt-out databases
  • Honor opt-out requests across all marketing channels
  • Document compliance procedures and maintain records

Time Zone Sensitivity

• Guam follows Chamorro Standard Time (UTC+10)
• Recommended Sending Hours: 8:00 AM to 8:00 PM local time
• Exception: Urgent messages like authentication codes or emergency alerts
• Consider cultural events and local holidays when scheduling campaigns

Phone Numbers Options and SMS Sender Types for in Guam

Alphanumeric Sender ID

Operator network capability: Not supported for dynamic usage
Registration requirements: N/A
Sender ID preservation: Sender IDs are typically overwritten by carrier default values

Long Codes

Domestic vs. International:

• Domestic long codes not supported
• International long codes supported but with limitations
• US long codes may be overwritten with different Sender IDs

Sender ID preservation: No, original Sender IDs are not preserved for long codes
Provisioning time: Immediate for international long codes
Use cases: Transactional messaging, alerts, and notifications

Short Codes

Support: Yes, through U.S. short code system
Provisioning time: 8-12 weeks for standard U.S. short code approval
Use cases:

• Marketing campaigns
• Two-factor authentication
• Customer service
• High-volume messaging

Restricted SMS Content, Industries, and Use Cases

Prohibited Content:

• Gambling and betting services
• Adult content
• Illegal products or services
• Cryptocurrency promotions without proper disclaimers
• Misleading or fraudulent content

Regulated Industries:

• Financial services require appropriate disclaimers
• Healthcare messages must comply with HIPAA
• Insurance products need clear terms and conditions

Content Filtering

Known Carrier Rules:

• URLs should be from approved domains
• Avoid excessive capitalization
• Limited use of special characters
• No mention of restricted keywords

Best Practices:

• Use approved URL shorteners
• Avoid spam trigger words
• Include clear business identification
• Maintain consistent sending patterns

Best Practices for Sending SMS in Guam

Messaging Strategy

• Keep messages under 160 characters when possible
• Include clear calls-to-action
• Personalize messages using recipient data
• Maintain consistent brand voice

Sending Frequency and Timing

• Limit to 2-4 messages per week per recipient
• Respect local holidays and cultural events
• Avoid sending during off-hours
• Space out bulk campaigns to prevent network congestion

Localization

• Support both English and Chamorro languages
• Consider cultural sensitivities in message content
• Use local date and time formats
• Include local contact information when possible

Opt-Out Management

• Process opt-outs in real-time
• Maintain centralized opt-out database
• Send confirmation of opt-out completion
• Regular audit of opt-out compliance

Testing and Monitoring

• Test across major Guam carriers
• Monitor delivery rates by carrier
• Track engagement metrics
• Regular testing of opt-out functionality
• Monitor for carrier filtering changes

SMS API integrations for Guam

Twilio

Twilio provides robust SMS capabilities for sending messages to Guam through their REST API.

Authentication:

• Account SID and Auth Token required
• Environment variables recommended for credential storage

Key Parameters:

• from: Your Twilio phone number
• to: Recipient number in E.164 format (+1671XXXXXXX)
• body: Message content

import * as Twilio from 'twilio';

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

async function sendSMSToGuam() {
  try {
    // Send message with error handling
    const message = await client.messages.create({
      body: 'Your message to Guam recipient',
      from: process.env.TWILIO_PHONE_NUMBER,
      to: '+1671XXXXXXX' // Guam number
    });
    
    console.log(`Message sent successfully: ${message.sid}`);
    return message;
  } catch (error) {
    console.error('Error sending message:', error);
    throw error;
  }
}

Sinch

Sinch offers SMS API access with support for Guam destinations.

Authentication:

• Project ID and API Token required
• Bearer token authentication

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

// Initialize Sinch client
const sinchClient = new SinchClient({
  projectId: process.env.SINCH_PROJECT_ID,
  keyId: process.env.SINCH_KEY_ID,
  keySecret: process.env.SINCH_KEY_SECRET
});

async function sendSinchSMS() {
  try {
    const response = await sinchClient.sms.batches.send({
      sendSMSRequestBody: {
        to: ['+1671XXXXXXX'],
        from: 'YourSenderID',
        body: 'Your message content'
      }
    });
    
    console.log('Message sent:', response);
    return response;
  } catch (error) {
    console.error('Sinch SMS error:', error);
    throw error;
  }
}

MessageBird

MessageBird (formerly referenced as "Bird") provides SMS capabilities for Guam.

Authentication:

• API Key required
• REST API access

import { initClient } from 'messagebird';

const messagebird = initClient(process.env.MESSAGEBIRD_API_KEY);

function sendMessageBirdSMS() {
  const params = {
    originator: 'YourSenderID',
    recipients: ['+1671XXXXXXX'],
    body: 'Your message content'
  };

  messagebird.messages.create(params, (err, response) => {
    if (err) {
      console.error('MessageBird error:', err);
      return;
    }
    console.log('Message sent:', response);
  });
}

Plivo

Plivo offers SMS API integration with support for Guam numbers.

Authentication:

• Auth ID and Auth Token required
• REST API implementation

import * as plivo from 'plivo';

const client = new plivo.Client(
  process.env.PLIVO_AUTH_ID,
  process.env.PLIVO_AUTH_TOKEN
);

async function sendPlivoSMS() {
  try {
    const response = await client.messages.create({
      src: 'YourPlivoNumber', // Your Plivo number
      dst: '+1671XXXXXXX',    // Destination number
      text: 'Your message content'
    });
    
    console.log('Message sent:', response);
    return response;
  } catch (error) {
    console.error('Plivo error:', error);
    throw error;
  }
}

API Rate Limits and Throughput

• Standard Rate Limits:
  • Twilio: 250 messages per second
  • Sinch: 30 messages per second
  • MessageBird: 60 messages per second
  • Plivo: 200 messages per second

Throughput Management Strategies:

• Implement queue systems for high-volume sending
• Use batch APIs when available
• Monitor delivery rates and adjust sending patterns
• Implement exponential backoff for retry logic

Error Handling and Reporting

• Implement comprehensive error logging
• Monitor delivery receipts
• Track common error codes
• Set up automated alerts for failure thresholds
• Maintain delivery status dashboard

Recap and Additional Resources

Key Takeaways

1. Compliance Priorities:

   • Obtain explicit consent
   • Honor opt-out requests
   • Follow TCPA guidelines
   • Respect local time zones

2. Technical Considerations:

   • Use E.164 number formatting
   • Implement proper error handling
   • Monitor delivery rates
   • Test across carriers

3. Best Practices:

   • Maintain clean contact lists
   • Regular compliance audits
   • Document consent records
   • Monitor performance metrics

Next Steps

1. Review Regulations:

   • TCPA compliance requirements
   • Guam-specific telecommunications laws
   • Data privacy regulations

2. Technical Setup:

   • Choose appropriate SMS provider
   • Implement proper error handling
   • Set up monitoring systems

3. Operational Preparation:

   • Develop content guidelines
   • Create response templates
   • Train support staff

Additional Information

• Guam Public Utilities Commission
• TCPA Compliance Guidelines
• SMS Best Practices