Phone Numbers in Denmark: A Comprehensive Guide

Quick Reference

• Country: Denmark
• Country Code: +45
• International Prefix: 00
• National Prefix: None

Overview

Denmark's telephone numbering plan is structured to facilitate easy dialing and number portability. This guide is an essential resource for telecom professionals, developers, and systems administrators seeking to understand Denmark's phone number formats, dialing procedures, and regulations.

Number Formats

General Structure

Denmark employs an 8-digit closed numbering plan without area codes. Phone numbers are formatted as XX XX XX XX, with X representing any digit from 0 to 9. The plan is non-geographic, meaning the initial digit does not denote a specific region.

Number Types and Formats

Detailed Number Structures

Landline Numbers

• Format: [2-9]X XX XX XX
• Examples: 3212 3456, 4912 3456
• Regular Expression: ^[2-9]\d{7}$

Mobile Numbers

• Format: [2-7]X XX XX XX
• Examples: 5123 4567, 6123 4567
• Regular Expression: ^[2-7]\d{7}$

Toll-Free Numbers

• Format: 80X XX XX XX
• Examples: 8080 1234
• Regular Expression: ^80\d{6}$

Premium Rate Numbers

• Format: 90X XX XX XX
• Examples: 9020 1234
• Regular Expression: ^90\d{6}$

Dialing Procedures

Domestic Calls

• Landline to Landline: Dial the 8-digit number directly.
• Landline to Mobile: Dial the 8-digit mobile number directly.
• Mobile to Mobile: Dial the 8-digit mobile number directly.

International Calls

• Outgoing: Dial 00 followed by the country code and the 8-digit number. For example, to call Denmark from abroad, dial +45 followed by the 8-digit number.
• Incoming: When receiving calls from abroad, the caller should dial +45 followed by the 8-digit number.

Number Portability

Introduced in 2001, number portability in Denmark allows users to keep their phone numbers when switching providers. This applies to all 8-digit numbers, facilitating consumer choice and competition.

Telecom Operators and Number Ranges

Denmark hosts several major telecom operators, each with specific number ranges. Although exact allocations are not publicly disclosed, the general structure includes:

• Mobile Phones: 20-31, 40-42, 50-55, 60-61, 71, 81, 91-93
• Landlines/ISDN: 32-36, 38-39, 43-49, 54-59, 62-66, 69, 72-79, 82, 86-89, 96-99

Regulatory Body

The Danish Energy Agency (Energistyrelsen), under the Ministry of Climate, Energy, and Utilities, regulates telecommunications in Denmark. They manage phone number allocation and ensure compliance with regulations. For more information, visit the Danish Energy Agency's official website.

ITU-T Standards

Denmark adheres to the ITU-T E.164 standard, ensuring international compatibility and consistency in phone number structures.

Number Allocation and Management

The Danish Energy Agency oversees the allocation and management of phone numbers, assigning them to telecom operators who distribute them to subscribers. Compliance with ITU-T recommendations is mandatory.

Technical Considerations

Regular Expressions for Validation

Developers can validate Danish phone numbers using these regular expression patterns:

// General Danish phone number pattern
const danishPhoneNumberPattern = /^[2-9]\d{7}$/;

// Mobile number pattern
const mobileNumberPattern = /^[2-7]\d{7}$/;

// Toll-free number pattern
const tollFreeNumberPattern = /^80\d{6}$/;

// Premium rate number pattern
const premiumRateNumberPattern = /^90\d{6}$/;

Number Blocking and Special Cases

Denmark does not impose specific technical restrictions such as golden numbers or number blocking. However, the Danish Energy Agency may enforce restrictions based on regulatory needs.

For the latest updates on telecommunications regulations in Denmark, please refer to the Danish Energy Agency's website.