Comprehensive Guide to Phone Numbers in Guernsey

Quick Reference

• Country: Guernsey
• Country Code: +44
• International Prefix: 00
• National Prefix: 0
• Regulatory Authority: Office of the Telecommunications Adjudicator (OTA)

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Overview

This guide offers an in-depth exploration of Guernsey's phone numbering system, detailing the structure, dialing procedures, and telecom regulations. It is an essential resource for telecom professionals, developers, and anyone needing comprehensive knowledge of Guernsey's telecom landscape.

Number Formats

Guernsey adheres to the UK's numbering plan with some unique distinctions. Below is a detailed breakdown of the number formats used in Guernsey:

General Number Structure

• Country Code: +44
• Area Code: 1481 (specific to Guernsey)
• Subscriber Number Length: 6 digits

Number Structure Breakdown

Type	Format	Example Number	Description
Geographic	+44 1481 XXXXXX	+44 1481 257895	Fixed-line numbers, typically used for landlines within Guernsey.
Mobile	+44 7XXX XXXXXX	+44 7781 123456	Mobile numbers, usually starting with 77, 78, or 79.
Toll-Free	+44 800 XXXXXX	+44 800 123456	Toll-free numbers, free for the caller within the UK and Guernsey.
Premium Rate	+44 9XX XXXXXX	+44 900 123456	Premium rate services, often used for special services or information lines.

Regular Expressions for Number Validation

• Geographic Numbers: ^\(\+44\s?1481\s?\d{6}\)$
• Mobile Numbers: ^\(\+44\s?7[7-9]\d{2}\s?\d{6}\)$
• Toll-Free Numbers: ^\(\+44\s?800\s?\d{6}\)$
• Premium Rate Numbers: ^\(\+44\s?9\d{2}\s?\d{6}\)$

Dialing Procedures

Domestic Calls

• Landline to Landline: Dial the full local number (e.g., 01481 257895).
• Landline to Mobile: Dial the mobile number directly (e.g., 07781 123456).
• Mobile to Mobile: Dial the mobile number directly (e.g., 07781 123456).

International Calls

• Outgoing: Dial 00, followed by the country code, area code (if applicable), and the subscriber number. For example, to call the USA: 00 1 212 5551234.
• Incoming: International callers should dial +44 1481 followed by the 6-digit subscriber number for landlines, or +44 7XXX followed by the 6-digit subscriber number for mobiles.

Number Portability

Guernsey supports number portability, allowing subscribers to retain their numbers when switching between service providers. This is managed by the Office of the Telecommunications Adjudicator (OTA).

Telecom Operators and Number Ranges

Operator	Number Range	Service Type
Sure	01481 2XXXXX	Landline
JT Group	01481 7XXXXX	Landline
Sure Mobile	07781 XXXXXX	Mobile
JT Mobile	07911 XXXXXX	Mobile

ITU-T Recommendations

Guernsey adheres to the ITU-T Recommendation E.164 for its numbering plan, ensuring global interoperability of its telephone numbers.

Number Allocation and Management

The numbering plan in Guernsey is managed by the Office of the Telecommunications Adjudicator (OTA). The OTA is responsible for the allocation, management, and regulation of telephone numbers within the jurisdiction.

Technical Restrictions and Special Cases

Golden Numbers

Guernsey does not have a formal policy on "golden numbers," which are numbers considered more desirable due to their memorable or aesthetically pleasing sequences. However, such numbers are sometimes reserved or auctioned by telecom operators.

Number Blocking

Guernsey's telecom operators may implement number blocking for specific services, such as premium-rate numbers, to protect consumers from fraud or excessive charges.

Technical Considerations for Developers

When handling Guernsey phone numbers in software systems:

1. Validation: Use the provided regular expressions to validate phone numbers accurately.
2. Formatting: Ensure numbers are stored in E.164 format (+44 1481 XXXXXX) to maintain consistency.
3. Portability: Account for number portability by not hardcoding operator-specific number ranges.
4. Internationalization: Implement logic to handle both local and international dialing formats.