Guernsey SMS Best Practices, Compliance, and Features

Guernsey SMS Market Overview

Locale name:	Guernsey
ISO code:	GG
Region	Europe
Mobile country code (MCC)	234
Dialing Code	+44

Market Conditions: Guernsey has a well-developed mobile telecommunications infrastructure, primarily served by local operators like Sure Guernsey and JT Guernsey. As part of the British Crown Dependencies, it follows similar telecommunications standards to the UK while maintaining its own regulatory framework. 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 Guernsey

Guernsey supports standard SMS messaging capabilities with some limitations on advanced features like two-way messaging and concatenation.

Two-way SMS Support

Two-way SMS is not supported in Guernsey through major SMS providers. This means businesses cannot receive replies to their SMS messages through standard A2P channels.

Concatenated Messages (Segmented SMS)

Support: Concatenated messaging is not supported in Guernsey through standard A2P channels.
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 GSM-7 being preferred for standard Latin alphabet messages to maximize character count.

MMS Support

MMS messages are automatically converted to SMS with an embedded URL link. This ensures compatibility while still allowing rich media content to be shared with recipients through a web-based interface.

Recipient Phone Number Compatibility

Number Portability

Number portability is not available in Guernsey. This means mobile numbers remain tied to their original carrier, which helps ensure more reliable message routing.

Sending SMS to Landlines

Sending SMS to landline numbers is not possible in Guernsey. Attempts to send messages to landline numbers will result in a 400 response error (code 21614), and the message will not be delivered or charged to your account.

Compliance and Regulatory Guidelines for SMS in Guernsey

SMS marketing in Guernsey is governed by the Data Protection (Bailiwick of Guernsey) Law, 2017 (DPL 2017) and the European Communities (Implementation of Privacy Directive) (Guernsey) Ordinance, 2004. The Office of the Data Protection Authority (ODPA) oversees compliance with these regulations.

Explicit Consent Requirements:

Consent must be specific, informed, and unambiguous
Pre-ticked boxes or silence do not constitute valid consent
Keep detailed records of when and how consent was obtained
Clearly state the purpose of communications during opt-in

Best Practices for Documentation:

Maintain timestamped records of all opt-in actions
Store the source and method of consent acquisition
Regularly audit and update consent records
Implement double opt-in for marketing communications

HELP/STOP and Other Commands

All SMS campaigns must support standard STOP commands
HELP messages should provide clear contact information
Keywords must be in English (primary language in Guernsey)
Process opt-out requests within 24 hours of receipt

Do Not Call / Do Not Disturb Registries

While Guernsey doesn't maintain its own Do Not Call registry, businesses should:

Honor UK's Telephone Preference Service (TPS) registrations
Maintain internal suppression lists
Implement immediate opt-out processing
Regularly clean contact databases

Time Zone Sensitivity

Guernsey follows British Time (GMT/BST). Best practices include:

Send messages between 8:00 AM and 8:00 PM local time
Respect local holidays and weekends
Avoid early morning or late evening messages
Only send urgent messages outside these hours

Phone Numbers Options and SMS Sender Types for in Guernsey

Alphanumeric Sender ID

Operator network capability: Supported with dynamic usage
Registration requirements: No pre-registration required
Sender ID preservation: Sender IDs are generally preserved across networks

Long Codes

Domestic vs. International: International long codes supported; domestic long codes not available
Sender ID preservation: Original sender ID preserved
Provisioning time: Immediate for international numbers
Use cases: Ideal for transactional messages and two-factor authentication

Short Codes

Support: Not supported in Guernsey
Provisioning time: N/A
Use cases: N/A

Restricted SMS Content, Industries, and Use Cases

Restricted Industries:

Gambling (requires special permits)
Adult content (prohibited)
Financial services (require regulatory compliance)
Healthcare (subject to data protection requirements)

Content Filtering

Carrier Filtering Rules:

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

Best Practices:

Use clear, professional language
Avoid spam trigger words
Include company name in message
Test messages before bulk sending

Best Practices for Sending SMS in Guernsey

Messaging Strategy

Keep messages under 160 characters when possible
Include clear call-to-action
Personalize using recipient's name
Maintain consistent brand voice

Sending Frequency and Timing

Limit to 2-4 messages per month per recipient
Respect Guernsey public holidays
Avoid sending during weekends
Space out campaigns appropriately

Localization

English is the primary language
Use British English spelling
Consider French for specific audiences
Adapt content for local context

Opt-Out Management

Process opt-outs within 24 hours
Maintain centralized opt-out database
Include clear opt-out instructions
Confirm opt-out with final message

Testing and Monitoring

Test across major local carriers
Monitor delivery rates regularly
Track engagement metrics
Analyze opt-out patterns
Conduct A/B testing for optimal performance

SMS API integrations for Guernsey

Twilio

Twilio provides a robust SMS API with comprehensive support for Guernsey numbers. Integration requires your Account SID and Auth Token from the Twilio Console.

import * as Twilio from 'twilio';

// Initialize Twilio client with authentication credentials
const client = new Twilio(
  process.env.TWILIO_ACCOUNT_SID,    // Your Account SID
  process.env.TWILIO_AUTH_TOKEN      // Your Auth Token
);

// Function to send SMS to Guernsey number
async function sendSMSToGuernsey(
  to: string,           // Recipient number in E.164 format (+44...)
  message: string,      // Message content
  from: string         // Your Twilio number or alphanumeric sender ID
) {
  try {
    const response = await client.messages.create({
      body: message,
      to: to,
      from: from,
    });
    console.log(`Message sent successfully! SID: ${response.sid}`);
    return response;
  } catch (error) {
    console.error('Error sending message:', error);
    throw error;
  }
}

Sinch

Sinch offers direct carrier connections for reliable message delivery to Guernsey. Authentication uses API key and secret.

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

// Initialize Sinch client
const sinchClient = new SinchClient({
  projectId: process.env.SINCH_PROJECT_ID,
  apiKey: process.env.SINCH_API_KEY,
  apiSecret: process.env.SINCH_API_SECRET
});

// Function to send SMS via Sinch
async function sendSinchSMS(
  recipientNumber: string,
  messageText: string,
  senderId: string
) {
  try {
    const response = await sinchClient.sms.batches.send({
      to: [recipientNumber],
      from: senderId,
      body: messageText,
      // Optional parameters for delivery reports
      deliveryReport: 'summary'
    });
    console.log('Message batch ID:', response.id);
    return response;
  } catch (error) {
    console.error('Sinch SMS Error:', error);
    throw error;
  }
}

MessageBird

MessageBird provides reliable SMS delivery to Guernsey with straightforward API integration.

import { MessageBirdClient } from 'messagebird';

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

// Function to send SMS via MessageBird
async function sendMessageBirdSMS(
  to: string,
  message: string,
  originator: string
): Promise<any> {
  return new Promise((resolve, reject) => {
    messagebird.messages.create({
      originator: originator,
      recipients: [to],
      body: message,
      // Optional parameters
      reportUrl: 'https://your-webhook-url.com/delivery-status'
    }, (err, response) => {
      if (err) {
        reject(err);
      } else {
        resolve(response);
      }
    });
  });
}

Plivo

Plivo offers reliable SMS delivery to Guernsey with comprehensive delivery reporting.

import * as plivo from 'plivo';

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

// Function to send SMS via Plivo
async function sendPlivoSMS(
  destination: string,
  message: string,
  sourceNumber: string
) {
  try {
    const response = await client.messages.create({
      src: sourceNumber,
      dst: destination,
      text: message,
      // Optional parameters
      url: 'https://your-webhook-url.com/delivery-status',
      method: 'POST'
    });
    console.log('Message UUID:', response.messageUuid);
    return response;
  } catch (error) {
    console.error('Plivo Error:', error);
    throw error;
  }
}

API Rate Limits and Throughput

Default rate limit: 1 message per second per destination
Batch sending limit: 100 messages per request
Daily sending quota: Based on account level

Strategies for Large-Scale Sending:

Implement queuing system for high-volume campaigns
Use batch APIs when available
Implement exponential backoff for retries
Monitor throughput and adjust sending rates

Error Handling and Reporting

Implement comprehensive logging for all API calls
Monitor delivery receipts via webhooks
Track common error codes and their resolutions
Set up automated alerts for failed deliveries

Recap and Additional Resources

Key Takeaways:

Always obtain explicit consent before sending marketing messages
Respect local time zones (GMT/BST) for message delivery
Implement proper opt-out handling
Monitor delivery rates and engagement metrics

Next Steps:

Review the Data Protection (Bailiwick of Guernsey) Law, 2017
Consult with legal counsel for compliance requirements
Set up test accounts with preferred SMS providers
Implement proper error handling and monitoring

Additional Resources:

Industry Guidelines:

Mobile Marketing Association Guidelines
GDPR-aligned best practices for data handling
Local telecommunications standards and regulations

American Samoa SMS Guide