Comprehensive Guide to Christmas Island Phone Numbers

Quick Reference

• Country: Christmas Island
• Country Code: +61
• International Prefix: 001[14-689]|14(?:1[14]|34|4[17]|[56]6|7[47]|88)0011
• National Prefix: 0

Overview

This guide provides an in-depth look at the telephone numbering plan, dialing procedures, and telecommunications regulations in Christmas Island. It is essential for telecom professionals, developers, and systems administrators who need a thorough understanding of the technical aspects of phone numbers in this region.

Number Formats

General Number Structure

Phone numbers in Christmas Island adhere to the Australian numbering plan, utilizing the country code +61. The typical structure includes:

• Country Code: +61
• Area Code: 1 or 2 digits (if applicable)
• Subscriber Number: 8 or 9 digits

Detailed Number Formats

Type	Format	Example	Description
Landline Numbers	8[1-9]XXXXXXX	891234567	Landline numbers start with '8' followed by 8 digits.
Mobile Numbers	4[0-9]XXXXXXX	412345678	Mobile numbers start with '4' and are followed by 8 digits.
Toll-Free Numbers	1800XXXXXX	1800123456	Toll-free numbers start with '1800' followed by 6 digits.
Premium Rate Numbers	190[0-9]XXXXXX	1900123456	Premium rate numbers start with '190X' followed by 6 digits.
Shared Cost Numbers	1300XXXXXX	1300123456	Shared cost numbers start with '1300' followed by 6 digits.

Regular Expressions for Number Validation

• Landline Numbers:
  ^8[1-9]\d{7}$
  

• Mobile Numbers:
  ^4\d{8}$
  

• Toll-Free Numbers:
  ^1800\d{6}$
  

• Premium Rate Numbers:
  ^190\d{6}$
  

• Shared Cost Numbers:
  ^1300\d{6}$
  

Dialing Procedures

Domestic Calls

• Landline to Landline: Dial the 8-digit subscriber number.
  • Example: 891234567
• Landline to Mobile: Dial the 9-digit mobile number.
  • Example: 412345678
• Mobile to Mobile: Dial the 9-digit mobile number.
  • Example: 412345678

International Calls

• Outgoing International Calls: Dial 0011 + Country Code + Area Code (if applicable) + Subscriber Number.
  • Example: To call the US: 0011 1 212 555 1234
• Incoming International Calls: Dial +61 followed by the local number without the leading 0.
  • Example: US caller dialing a Christmas Island number: +61 891234567

Recent Changes to the Numbering Plan

As of the latest updates, there have been no significant changes to the numbering plan in Christmas Island. The system remains aligned with Australia's telecommunications framework.

Number Portability

Currently, Christmas Island does not have a specific mobile number portability system. However, Australian telecommunications regulations, which may include number portability, could apply.

Major Telecom Operators and Number Ranges

Christmas Island’s telecommunications services are provided by major Australian operators:

• Telstra: Dominates landline and mobile services.
• Optus: Offers mobile services.
• Vodafone: Provides mobile services.

ITU Recommendations

Christmas Island complies with the ITU-T Recommendation E.164, defining the international public telecommunication numbering plan.

Number Allocation and Management

The Australian Communications and Media Authority (ACMA) oversees the allocation and management of phone numbers in Christmas Island, ensuring efficient use of numbering resources in line with international standards.

Technical Restrictions and Special Cases

• Golden Numbers: Special premium numbers with memorable sequences may be available, subject to availability and pricing by telecom operators.
• Number Blocking: Certain number ranges may be blocked for security or regulatory reasons, though no specific cases have been reported for Christmas Island.

Technical Considerations for Developers

When developing systems for Christmas Island phone numbers, consider the following:

• Validation: Use the provided regular expressions for phone number validation.
• Internationalization: Ensure systems can handle the +61 country code and removal of the leading 0 for international calls.
• Portability: While number portability may not be widely implemented, systems should be designed to accommodate potential future changes.