International Phone Validation: Handling Global Number Formats

International phone validation requires understanding diverse numbering plans, cultural conventions, and regulatory requirements. Building globally compatible validation systems demands comprehensive knowledge of regional variations and standards.

International Phone Validation Overview

Overview {#overview}

Phone number formats vary dramatically by country, requiring country-specific validation rules. ITU-T E.164 provides the global framework, but implementation requires handling regional numbering plans, formatting conventions, and carrier-specific patterns.

E.164 Standard {#e164-standard}

International standard for phone numbering.

interface E164Number {
  countryCode: string // 1-3 digits
  nationalNumber: string // Up to 15 total digits
  formatted: string
}

function parseE164(number: string): E164Number {
  const cleaned = number.replace(/D/g, '')
  const countryCode = cleaned.slice(0, 1) // Simplified
  const nationalNumber = cleaned.slice(1)
  
  return {
    countryCode,
    nationalNumber,
    formatted: `+${countryCode} ${nationalNumber}`
  }
}

Country-Specific Rules {#country-rules}

Different countries have different validation rules.

interface CountryRules {
  code: string
  minLength: number
  maxLength: number
  pattern: RegExp
  format: string
}

const COUNTRY_RULES: Record<string, CountryRules> = {
  'US': {
    code: '+1',
    minLength: 10,
    maxLength: 10,
    pattern: /^[2-9]d{2}[2-9]d{6}$/,
    format: '(XXX) XXX-XXXX'
  },
  'UK': {
    code: '+44',
    minLength: 10,
    maxLength: 10,
    pattern: /^[1-9]d{9}$/,
    format: 'XXXX XXX XXXX'
  },
  'DE': {
    code: '+49',
    minLength: 10,
    maxLength: 11,
    pattern: /^[1-9]d{9,10}$/,
    format: 'XXX XXXXXXXX'
  }
}

Number Formatting {#formatting}

Format numbers according to local conventions.

class PhoneFormatter {
  format(number: string, country: string): string {
    const rules = COUNTRY_RULES[country]
    if (!rules) return number
    
    const cleaned = number.replace(/D/g, '')
    let formatted = rules.code + ' '
    
    // Apply country-specific formatting
    // Simplified implementation
    return formatted + cleaned
  }
}

Validation Implementation {#validation}

Validate phone numbers globally.

class InternationalPhoneValidator {
  validate(number: string, expectedCountry?: string): {
    valid: boolean
    country: string
    formatted: string
  } {
    const cleaned = number.replace(/D/g, '')
    
    for (const [country, rules] of Object.entries(COUNTRY_RULES)) {
      if (expectedCountry && country !== expectedCountry) continue
      
      const nationalNumber = cleaned.replace(rules.code.replace('+', ''), '')
      
      if (nationalNumber.length >= rules.minLength && 
          nationalNumber.length <= rules.maxLength &&
          rules.pattern.test(nationalNumber)) {
        return {
          valid: true,
          country,
          formatted: rules.code + ' ' + nationalNumber
        }
      }
    }
    
    return { valid: false, country: 'unknown', formatted: number }
  }
}

Conclusion {#conclusion}

International phone validation requires understanding E.164 standard, implementing country-specific rules, handling diverse formatting conventions, and providing appropriate user feedback. Success depends on maintaining comprehensive country rules, supporting multiple input formats, and providing clear formatting guidance.

Validate phone numbers globally with our international phone validation APIs, supporting 200+ countries with accurate, country-specific validation rules.

International Phone Validation: Handling Global Number Formats

Table of Contents

Table of Contents

International Phone Validation: Handling Global Number Formats

Overview {#overview}

E.164 Standard {#e164-standard}

Country-Specific Rules {#country-rules}

Number Formatting {#formatting}

Validation Implementation {#validation}

Conclusion {#conclusion}