Understanding Czechia Phone Numbers: Formats and Dialing Rules

Quick Reference Guide

• Country: Czechia
• Country Code: +420
• International Prefix: 00
• National Prefix: None
• Numbering Plan Type: Closed numbering plan
• Regulatory Authority: Český Telekomunikační Úřad (CTU)

Overview

Discover the intricacies of Czechia's telephone numbering system with this detailed guide. Perfect for telecom professionals, developers, and system administrators, it covers phone number structures, dialing procedures, and essential telecommunications data.

Number Formats in Czechia

Czechia employs a closed numbering plan, ensuring all phone numbers are fixed-length and require no national prefix for domestic calls. The plan includes various services like geographic, mobile, and special service numbers.

General Phone Number Structure

• Format: +420 NXX XXX XXX
• Length: 9 digits (excluding the country code)
• Country Code: +420
• N: Represents the type of service or geographic area

Geographic Numbers (Landlines)

Mobile Numbers

Toll-Free Numbers

• Format: 800 XXX XXX
• Example: 800 123 456

Premium Rate Numbers

• Format: 90X XXX XXX
• Example: 900 123 456

Shared Cost Numbers

• Format: 8[134]X XXX XXX
• Example: 811 123 456

Special Services and Emergency Numbers

• Emergency Services: 112
• Directory Enquiries: 118X

Numbering Scheme (Regular Expressions)

For developers and system administrators, use these regular expressions to validate Czechia phone numbers:

// General Czechia Number Format
/^(
+420)?[2-9]\d{8}$/

// Geographic Numbers (Landlines)
/^(
+420)?(2|3[1257-9]|4[16-9]|5[13-9])\d{7}$/

// Mobile Numbers
/^(
+420)?(60[1-8]|7[023-9])\d{6}$/

// Toll-Free Numbers
/^(
+420)?800\d{6}$/

// Premium Rate Numbers
/^(
+420)?90[05689]\d{6}$/

// Shared Cost Numbers
/^(
+420)?8[134]\d{7}$/

Dialing Procedures

Domestic Calls

• Landline to Landline: Dial the full 9-digit number.
• Landline to Mobile: Dial the full 9-digit number.
• Mobile to Mobile: Dial the full 9-digit number.

International Calls

• Outgoing: Dial 00 followed by the country code, and then the full national number.
• Incoming: Dial +420 followed by the 9-digit local number.

Number Portability

Czechia supports number portability, allowing users to keep their numbers when switching providers. This applies to both mobile and fixed-line numbers, regulated by the Český Telekomunikační Úřad (CTU).

Major Telecom Operators and Number Ranges

Number Allocation and Management

The Český Telekomunikační Úřad (CTU) oversees phone number allocation and management in Czechia, ensuring compliance with ITU-T E.164 standards.

Technical Considerations

For Developers and Systems Administrators

• Number Validation: Utilize the provided regular expressions for Czechia phone number validation.
• Portability Handling: Implement logic to manage number portability, especially for mobile numbers where prefixes may not indicate the current provider.
• Emergency Services: Ensure systems recognize and route calls to emergency numbers like 112.
• Internationalization: Always include the +420 country code for international calls.