Guinea Phone Numbers: Format, Area Code & Validation Guide

This guide covers Guinea's phone number system for developers, telecommunications professionals, and anyone working with Guinea phone numbers and the +224 country code. Guinea's telecommunications sector serves over 14 million mobile subscribers (2024), with mobile penetration exceeding 100% of the population. You'll learn number formats based on the E.164 standard (the international public telecommunication numbering plan maintained by ITU-T), validation techniques, best practices, and future developments in the Guinean telecommunications landscape.

Quick Reference

• Country: Guinea
• Country Code: +224
• International Prefix: 00
• National Prefix: None
• Typical Number Length: 9 digits (excluding country code)
• Emergency Numbers: Police (17), Fire (18), Medical (15)
• Time Zone: GMT (UTC+0)
• Currency Code: GNF (Guinean Franc)

Phone Number Formats in Guinea

What is E.164?

E.164 is the international standard for public telephone numbering established by the International Telecommunication Union (ITU-T). It defines a unique structure for phone numbers worldwide, enabling global call routing and interoperability between telecommunications networks. An E.164-compliant number consists of:

• A country code (1–3 digits)
• A subscriber number (up to 15 digits total, including country code)
• No spaces, hyphens, or other separators in the canonical form
• A '+' prefix to indicate international format

Why E.164 matters: E.164 format ensures your application can handle international calls, integrate with global SMS/voice APIs, and maintain consistent data across systems. Non-standard formats cause routing failures, validation errors, and poor user experience.

Guinea Phone Number Structure (+224)

Guinea follows the E.164 standard with this structure:

• Country Code: +224 (assigned by ITU-T)
• Subscriber Number: 9 digits

Common formatting mistakes to avoid:

• ❌ 224622345678 (missing '+' prefix)
• ❌ +224 622 345 678 (spaces in E.164 canonical form)
• ❌ 00224622345678 (using international dial prefix instead of '+')
• ❌ 622345678 (missing country code for international storage)
• ✅ +224622345678 (correct E.164 format)

The subscriber number breaks down by service type: landline or mobile.

Guinea Landline Phone Numbers

• Format: 3XXXXXXX (9 digits including the leading '3')
• Geographic Zoning: The second digit signifies the region:
  • 0–2: Conakry (capital city)
  • 3–4: Maritime Guinea (Kindia, Boké regions)
  • 5–6: Middle Guinea (Labé, Mamou regions)
  • 7–8: Upper Guinea (Kankan, Siguiri regions)
  • 9: Forest Guinea (Nzérékoré region)
• Full E.164 Example: +22430243123 (a Conakry landline)
• Coverage: Landline penetration remains low (<1% of population), concentrated in urban areas, particularly Conakry.

Guinea Mobile Phone Numbers

• Format: 6XXXXXXX (9 digits including the leading '6')
• Full E.164 Example: +224622345678

Operator Prefix Ranges (as of 2024):

The second and third digits after '6' traditionally indicate the mobile operator:

• Orange Guinea: 62x, 64x, 65x (e.g., 620, 621, 640–649, 650–659)
• MTN Guinea: 66x, 67x (e.g., 660–669, 670–679) – Note: MTN Guinea faced regulatory disputes with ARPT in 2021–2023 regarding license compliance; service continues under regulatory oversight
• Cellcom Guinea: 61x, 63x (e.g., 610–619, 630–639)

Important validation considerations:

• Number portability discussions are ongoing with ARPT, which would allow users to keep numbers when switching operators
• Use operator prefix identification for informational purposes only (e.g., optimizing routing costs), not as a validation requirement
• Always validate against the general format 6XXXXXXX rather than operator-specific ranges to future-proof your implementation

How to Validate Guinea Phone Numbers

Robust phone number validation prevents data entry errors, reduces SMS/call failures, and maintains data quality. Here's a JavaScript function for validating Guinea phone numbers:

function validateGuineaNumber(number, type) {
  // Remove non-digit characters (spaces, hyphens, parentheses)
  const cleanNumber = number.replace(/\D/g, '');

  // Define validation patterns
  const patterns = {
    landline: /^3\d{7}$/,      // Starts with 3, followed by exactly 7 more digits
    mobile: /^6\d{7}$/,        // Starts with 6, followed by exactly 7 more digits
    emergency: /^(15|17|18)$/  // Exactly 15, 17, or 18
  };

  // Test against the appropriate pattern
  return patterns[type]?.test(cleanNumber) || false;
}

// Example usage:
console.log(validateGuineaNumber('30243123', 'landline')); // true
console.log(validateGuineaNumber('+224622345678', 'mobile')); // true
console.log(validateGuineaNumber('17', 'emergency')); // true
console.log(validateGuineaNumber('622-345-678', 'mobile')); // true (handles hyphens)

Regex pattern explanation:

• ^ – Start of string
• 3 or 6 – Required first digit
• \d{7} – Exactly 7 additional digits (0–9)
• $ – End of string
• This ensures exactly 8 digits total for the cleaned number

Error Handling Best Practices

When validation fails, provide actionable feedback:

function validateWithErrorHandling(number, type) {
  const cleanNumber = number.replace(/\D/g, '');

  // Check length first
  if (cleanNumber.length === 0) {
    return { valid: false, error: 'Enter a phone number' };
  }

  // Remove country code if present
  const subscriberNumber = cleanNumber.startsWith('224')
    ? cleanNumber.slice(3)
    : cleanNumber;

  // Validate length
  if (subscriberNumber.length !== 8 && !['15', '17', '18'].includes(subscriberNumber)) {
    return {
      valid: false,
      error: `Guinea phone numbers must be 8 digits (found ${subscriberNumber.length})`
    };
  }

  // Validate prefix
  const prefix = subscriberNumber.charAt(0);
  const expectedPrefix = type === 'landline' ? '3' : type === 'mobile' ? '6' : null;

  if (expectedPrefix && prefix !== expectedPrefix) {
    return {
      valid: false,
      error: `${type} numbers must start with ${expectedPrefix} (found ${prefix})`
    };
  }

  return { valid: true, formatted: `+224${subscriberNumber}` };
}

// Usage with error handling
const result = validateWithErrorHandling('522345678', 'mobile');
if (!result.valid) {
  console.error(result.error); // "mobile numbers must start with 6 (found 5)"
}

Validation timing and security:

• Client-side validation: Provide immediate user feedback, but never rely on it exclusively
• Server-side validation: Always re-validate on the server to prevent malicious input and data corruption
• Rate limiting: Implement rate limits on validation endpoints to prevent abuse
• Sanitization: Always sanitize input before validation to prevent injection attacks

Key Validation Considerations:

• International Format: The provided function handles numbers with or without the country code. Always store numbers in international format (+224XXXXXXXX) for consistency and global compatibility.
• Hyphens and Spaces: Strip these before validation, as demonstrated in the example.
• Edge Cases: Consider how your application will handle invalid input, providing clear error messages to the user.

Validation in Other Languages

Python:

import re

def validate_guinea_number(number: str, number_type: str) -> bool:
    """Validate Guinea phone numbers."""
    clean_number = re.sub(r'\D', '', number)

    # Remove country code if present
    if clean_number.startswith('224'):
        clean_number = clean_number[3:]

    patterns = {
        'landline': r'^3\d{7}$',
        'mobile': r'^6\d{7}$',
        'emergency': r'^(15|17|18)$'
    }

    pattern = patterns.get(number_type)
    return bool(pattern and re.match(pattern, clean_number))

PHP:

function validateGuineaNumber(string $number, string $type): bool {
    // Remove non-digit characters
    $cleanNumber = preg_replace('/\D/', '', $number);

    // Remove country code if present
    if (str_starts_with($cleanNumber, '224')) {
        $cleanNumber = substr($cleanNumber, 3);
    }

    $patterns = [
        'landline' => '/^3\d{7}$/',
        'mobile' => '/^6\d{7}$/',
        'emergency' => '/^(15|17|18)$/'
    ];

    return isset($patterns[$type]) && preg_match($patterns[$type], $cleanNumber) === 1;
}

Formatting Guinea Numbers to E.164 Standard

When to use E.164 formatting:

• Data storage: Store all phone numbers in E.164 format in databases for consistency
• API integration: Most SMS/voice APIs (Twilio, Vonage, etc.) require E.164 format
• International calls: Required for proper call routing across networks
• Data deduplication: E.164 format ensures "+224622345678" and "622-345-678" are recognized as identical

Consistent phone number formatting is essential for international telecommunications. Here's an improved function to format any Guinea number to the E.164 standard:

function formatGuineaE164(number) {
  // Remove all non-digit characters
  let cleanNumber = number.replace(/\D/g, '');

  // Remove leading zeros
  cleanNumber = cleanNumber.replace(/^0+/, '');

  // Remove country code if already present (224 or 00224)
  if (cleanNumber.startsWith('224')) {
    cleanNumber = cleanNumber.slice(3);
  }

  // Validate cleaned number is exactly 8 digits
  if (!/^\d{8}$/.test(cleanNumber)) {
    throw new Error(`Invalid Guinea number: expected 8 digits, got ${cleanNumber.length}`);
  }

  // Return E.164 format
  return `+224${cleanNumber}`;
}

// Examples
console.log(formatGuineaE164('622345678'));        // +224622345678
console.log(formatGuineaE164('+224622345678'));    // +224622345678 (idempotent)
console.log(formatGuineaE164('00224622345678'));   // +224622345678
console.log(formatGuineaE164('622-345-678'));      // +224622345678

Guinea Mobile Operators and Network Coverage

Guinea's mobile telecommunications market is primarily served by Orange Guinea, MTN Guinea, and Cellcom Guinea. While specific number ranges have been associated with these operators in the past, relying on these for phone number validation is discouraged due to the potential for number portability. Always prioritize validation against the general format (6XXXXXXX).

Market Overview (2024 estimates):

• Orange Guinea: ~50–55% market share, strongest 4G coverage in Conakry and major cities
• MTN Guinea: ~30–35% market share, extensive rural coverage
• Cellcom Guinea: ~10–15% market share, competitive urban pricing

Historical number ranges:

• Orange Guinea: Historically associated with ranges like 620–629, 640–649, 650–659
• MTN Guinea: Historically associated with ranges like 660–669, 670–679 Note: MTN Guinea faced regulatory disputes with ARPT (2021–2023) over license fee payments and regulatory compliance. The dispute led to temporary service disruptions and threats of license revocation. As of 2024, MTN continues operations under ongoing regulatory oversight. Don't rely on MTN's continued market presence for long-term number planning.
• Cellcom Guinea: Historically associated with ranges like 610–619, 630–639

Important considerations:

• Operator identification by prefix may become unreliable if number portability is implemented
• For SMS delivery optimization, query carrier lookup APIs rather than relying on prefix-based routing
• Coverage and quality vary significantly between urban (good) and rural (limited) areas

Future Changes to Guinea's Numbering Plan

The Guinea telecommunications landscape is evolving. Key developments to watch for Guinea phone numbers:

• Guinée Telecom Relaunch: The government is working to relaunch the former incumbent operator, Sotelgui, under the name Guinée Telecom. This could introduce new number ranges or prefixes (potentially 68x or 69x ranges). Timeline: Uncertain; project announced 2022, no commercial launch date confirmed as of 2024.

• Number Portability: The ARPT (Autorité de Régulation des Postes et Télécommunications) is exploring the implementation of number portability. This would allow subscribers to keep their numbers when switching operators, making operator identification based on prefixes unreliable. Timeline: Regulatory framework under development; implementation unlikely before 2026.

• Infrastructure Improvements: Investments in fiber optic infrastructure and a national backbone network are underway, promising improved connectivity and potentially new service offerings (VoIP, IoT). Status: Ongoing, with submarine cable landings improving international capacity.

How to prepare:

1. Decouple validation from operator identification: Never validate numbers based on specific operator prefixes (e.g., rejecting 69x numbers). Use only the general format ^6\d{7}$.

2. Use carrier lookup APIs: For features requiring operator identification (SMS routing optimization, cost calculation), integrate with real-time carrier lookup services (HLR/MNP lookup) rather than static prefix tables.

3. Version your validation logic: Tag validation rules with version numbers and effective dates to enable rollback if number plan changes cause issues.

4. Monitor ARPT announcements: Subscribe to ARPT updates or implement periodic checks against authoritative numbering plan sources.

5. Test with placeholder ranges: When testing, use numbers from reserved ranges (e.g., 699900000–699999999) to avoid accidentally contacting real subscribers.

6. Plan for longer numbers: While not currently planned, keep your database schema flexible (store E.164 as VARCHAR(15) or larger) to accommodate future number plan expansions.

Stay up to date: Refer to the ARPT website for the latest regulatory information and updates on these developments. For technical numbering plan details, consult the ITU-T E.164 assignment database.

Best Practices for Guinea Phone Number Implementation

Validation and Storage

• Always validate user input: Validate both client-side (for UX) and server-side (for security and data integrity). Never trust client-side validation alone.

• Store numbers in international E.164 format: Use +224XXXXXXXX format in databases. This enables:

  • Global compatibility and call routing
  • Easy integration with SMS/voice APIs
  • Consistent data for deduplication and matching
  • Future-proofing against numbering plan changes

• Handle invalid numbers gracefully: Provide informative error messages that guide users toward correct input:

  • ❌ "Invalid number" (not helpful)
  • ✅ "Mobile numbers must start with 6 and contain 8 digits (e.g., 622345678)"

Testing and Quality Assurance

• Use test number ranges: Coordinate with operators or use high-value test ranges (699900000–699999999) to avoid contacting real subscribers during development and QA.

• Test edge cases systematically:

  • Numbers with country code vs. without
  • Numbers with various formatting (spaces, hyphens, parentheses)
  • Numbers already in E.164 format (ensure idempotency)
  • Invalid lengths, prefixes, and characters
  • Empty input and null values

• Load testing: For high-volume applications (SMS gateways, call centers), test validation performance:

  • Benchmark regex validation (typically <0.1ms per number)
  • Cache compiled regex patterns in production
  • Consider batch validation for bulk imports

International Dialing

• Display formatting: Show users numbers in familiar local format 6XX XX XX XX in the UI, but store as +224XXXXXXXX internally.

• Input flexibility: Accept multiple input formats but normalize to E.164:

  • Local format: 622345678
  • International with prefix: 00224622345678
  • E.164: +224622345678
  • Formatted: 622-345-678 or 6 22 34 56 78

• Click-to-call links: Use the tel: URI scheme with E.164 format for maximum compatibility:

  markup

  &lt;a href="tel:+224622345678"&gt;Call +224 6 22 34 56 78</a&gt;
  

Regulatory Compliance and Monitoring

• Stay informed about regulatory changes: Monitor ARPT announcements and adapt your implementations accordingly. Subscribe to telecommunications industry updates for Guinea.

• Log validation failures: Track validation errors to identify data quality issues, user confusion patterns, or potential numbering plan changes.

• Consider using a dedicated phone number validation library: For production applications requiring global support, consider libraries like:

  • libphonenumber (Google's library, supports 200+ countries)
  • phonelib (Ruby wrapper for libphonenumber)
  • python-phonenumbers (Python port)

  These libraries handle edge cases, provide carrier lookup, and receive regular updates for numbering plan changes.

Performance Optimization

• Cache validation results: For repeated validations of the same number (e.g., in a user session), cache results with appropriate TTL.

• Database indexing: Index phone number columns for fast lookups, using exact match indexes on E.164 format fields.

• Bulk operations: When validating or formatting thousands of numbers (imports, migrations), process in batches and use efficient string operations.

Follow these guidelines to ensure your applications handle Guinea phone numbers correctly, providing a seamless experience for your users while maintaining data quality and regulatory compliance.