Guernsey Phone Numbers: Format, Area Code & Validation Guide

This guide provides a detailed overview of Guernsey phone numbers, covering formatting, area codes, validation, special services, dialing codes, number portability, and essential information for developers integrating telecommunications functionalities into their applications.

Number Formatting and Area Codes

Guernsey follows the UK's National Telephone Numbering Plan, using the international dialing code +44. The area code for Guernsey is 1481. Understanding the correct format is crucial for successful communication and integration.

• Landline Numbers: +44 1481 XXXXXX (where XXXXXX represents a six-digit local number).
• Mobile Numbers: +44 7XXX XXXXXX (where 7XXX represents the mobile network prefix and XXXXXX represents a six-digit local number. Mobile prefixes in use include 7781, 7839, and 7911, among others).

Example: A typical Guernsey landline number might look like +44 1481 234567, while a mobile number could be +44 7781 123456.

Number Validation

Validating user-provided phone numbers is essential for any application. Here's a robust JavaScript snippet for validating Guernsey numbers:

const validateGuernseyNumber = (number) => {
  const cleanedNumber = number.replace(/\s/g, ''); // Remove whitespace
  if (cleanedNumber.match(/^\+441481\d{6}$/)) {
    return { valid: true, type: 'landline' };
  } else if (cleanedNumber.match(/^\+447[7-9]\d{2}\d{6}$/)) {
    return { valid: true, type: 'mobile' };
  } else {
    return { valid: false, type: null };
  }
};

// Example usage:
console.log(validateGuernseyNumber('+44 1481 234567')); // { valid: true, type: 'landline' }
console.log(validateGuernseyNumber('+447781123456')); // { valid: true, type: 'mobile' }
console.log(validateGuernseyNumber('+44 1234567890')); // { valid: false, type: null }

This function not only validates the format but also identifies the number type (landline or mobile). Remember to handle invalid numbers gracefully in your application.

Special Services and Dialing Codes

Guernsey offers a range of special services accessible through specific dialing codes.

Emergency Services

• 999 or 112: These numbers connect you to emergency services (police, fire, ambulance). Use these numbers only in genuine emergencies. Misuse can result in penalties.
• 01481 725111: This is the non-emergency number for the police. Use this for situations that require police assistance but are not immediate emergencies.

Other Important Services

• 01481 725241: Princess Elizabeth Hospital (for general inquiries and emergencies). For non-emergency medical services, contact your local provider directly. Contact information can often be found through the States of Guernsey Official Directory (https://www.gov.gg/contactus).

Directory Services

• 118XXX: Traditional directory enquiry services (charges apply).
• States of Guernsey Official Directory (https://www.gov.gg/contactus): An online resource for finding government and public service contact information.

Value-Added Services

Guernsey offers value-added services, many aligning with UK standards. These include shortcodes for information (2580XX), banking (159XX), weather (1622XX), and traffic (1623XX), as well as premium-rate numbers starting with 09. Consult your service provider for specific shortcodes and premium-rate number details.

Telecommunications Providers

Guernsey's telecommunications infrastructure is primarily supported by two major providers:

• Sure Guernsey (https://www.sure.com/guernsey/): With a history dating back to 1898 (originally the States Telephone Department), Sure offers a comprehensive range of services, including mobile, landline, broadband, and business solutions. They are currently undertaking a significant fiber-optic broadband rollout.
• JT Global (https://www.jtglobal.com/jt-help/category/guernsey/): JT provides a portfolio of modern digital services, including mobile, broadband, and international connectivity solutions.

Voicemail Services

Both Sure and JT offer voicemail services for landlines and mobiles. Access codes and setup procedures may vary. Check with your provider for specific instructions.

Developer Implementation Guide

Number Portability

Number portability allows users to switch providers while keeping their existing number. The process typically takes 5 business days but can take longer in complex cases. The Office of the Telecommunications Adjudicator (OTA) (https://www.offta.org.uk/best-practice-guide) oversees number portability in Guernsey.

Best Practices for Service Integration

• Robust Error Handling: Implement comprehensive error handling to manage invalid numbers, service disruptions, and other potential issues.
• Provider-Specific APIs: Use provider APIs for functionalities like SMS messaging, call routing, and number lookup. Ensure proper authentication and authorization.
• Fallback Options: Plan for service disruptions by implementing fallback mechanisms.
• Emergency Number Routing: Rigorously test emergency number routing to ensure reliable functionality.
• Cross-Border Compatibility: Handle international dialing codes and ensure compatibility with UK number formatting standards. Consider specific requirements for the Channel Islands.

Cost Structure

Telecommunications costs in Guernsey vary by provider and service type. Local calls typically start from £0.02/minute, mobile calls from £0.10/minute, and SMS messages from £0.05/message. Data services are usually package-dependent. Premium services like directory enquiries and premium-rate calls incur higher charges. Always consult your service provider's current rate card for detailed pricing information.

This comprehensive guide should equip developers with the necessary information to effectively work with Guernsey phone numbers. Remember to consult the official documentation and resources of the relevant telecommunications providers for the most up-to-date details and specific implementation guidelines.