Understanding Phone Numbers in Singapore

Quick Facts

• Country: Singapore
• Country Code: +65
• International Dialing Prefix: 00
• National Dialing Prefix: None

Comprehensive Overview

This guide offers an in-depth look into Singapore's telephone numbering plan, detailing number formats, dialing procedures, and regulatory insights. It's tailored for telecom experts, developers, and system administrators seeking accurate and current technical information about Singapore's numbering system.

Number Formats in Singapore

General Structure

Singapore employs a closed numbering plan, meaning there are no area codes due to its compact geographical area. All phone numbers are 8 digits long and require the country code (+65) for international calls.

• Format: [XXXX XXXX]
• Country Code: +65
• Subscriber Number Length: 8 digits

Specific Number Types

Validating Phone Numbers

Use the following regular expressions to validate Singapore phone numbers:

• Landline: ^6\d{7}$
• Mobile: ^[89]\d{7}$
• Toll-Free: ^800\d{7}$
• Premium Rate: ^1900\d{7}$

Example JavaScript Validation Function

function validateSGPhoneNumber(number) {
    const landlinePattern = /^6\d{7}$/;
    const mobilePattern = /^[89]\d{7}$/;
    const tollFreePattern = /^800\d{7}$/;
    const premiumRatePattern = /^1900\d{7}$/;

    return landlinePattern.test(number) || 
           mobilePattern.test(number) || 
           tollFreePattern.test(number) || 
           premiumRatePattern.test(number);
}

Dialing Procedures

Domestic Calls

• Landline to Landline: Dial the 8-digit number directly (e.g., 6123 4567).
• Landline to Mobile: Dial the 8-digit mobile number directly (e.g., 9123 4567).
• Mobile to Mobile: Dial the 8-digit mobile number directly (e.g., 9123 4567).

International Calls

Outgoing

• Format: 00 + [Country Code] + [Subscriber Number]
• Example: To call a number in the US, dial 001 + [Area Code] + [Local Number].

Incoming

• Format: +65 + [Local 8-Digit Number]
• Example: +65 9123 4567

Number Portability

Singapore has enabled number portability for both mobile and fixed-line numbers since 2003. This allows users to keep their phone numbers when switching providers, managed by the Info-communications Media Development Authority (IMDA).

Major Telecom Operators

Note: Specific number ranges are managed by IMDA.

Regulatory Body

The Info-communications Media Development Authority (IMDA) oversees telecommunications in Singapore, ensuring compliance with international standards and managing phone number allocations.

Recent Changes and Technical Considerations

Stability and Management

The numbering plan has remained stable over the past five years, with IMDA efficiently managing allocations and ensuring future growth.

ITU-T Recommendations

Singapore adheres to ITU-T E.164 standards for international numbering, ensuring global compatibility.

Special Cases

• Golden Numbers: Premium numbers with repeating digits may be available at a higher cost.
• Emergency Numbers: 999 (Police), 995 (Fire/Ambulance), 1777 (Non-emergency Ambulance).