Mobile Line Verification 2026: Filter Landlines for 96% SMS Deliverability

// Mobile Line Verification API
async function verifyMobileLine(phoneNumber) {
  const response = await fetch(
    'https://api.phone-check.app/v1/validate',
    {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Authorization': 'Bearer YOUR_API_KEY'
      },
      body: JSON.stringify({
        phone: phoneNumber,
        include_line_type: true,
        include_carrier: true
      })
    }
  );

  const data = await response.json();

  // Line type classification
  const lineType = data.line_type; // mobile, fixed_line, voip, toll_free, premium_rate

  // SMS capability assessment
  const smsCapable = {
    mobile: true,           // Always SMS-capable
    fixed_line: false,      // Cannot receive SMS
    voip: data.voip_sms_capable || false, // Check provider
    toll_free: data.toll_free_sms || false,
    premium_rate: false,    // Block for campaigns
    unknown: false          // Treat as non-capable
  };

  return {
    phoneNumber: data.phone,
    lineType: lineType,
    carrier: data.carrier_name,
    smsCapable: smsCapable[lineType] || false,
    countryCode: data.country_code,
    formatted: data.formatting?.international
  };
}

// Advanced Mobile Line Classification
async function classifyForSmsCampaign(phoneNumber) {
  const response = await fetch(
    'https://api.phone-check.app/v1/phone-details',
    {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Authorization': 'Bearer YOUR_API_KEY'
      },
      body: JSON.stringify({
        phone: phoneNumber,
        include_line_type: true,
        include_carrier: true,
        include_portability: true
      })
    }
  );

  const data = await response.json();

  // Classification rules
  const classification = {
    // Tier 1: Best for SMS (Mobile wireless)
    tier1: data.line_type === 'mobile' &&
           !data.is_mvno && // Major carrier, not MVNO
           data.carrier_type === 'mobile',

    // Tier 2: Good for SMS (Mobile MVNOs)
    tier2: data.line_type === 'mobile' &&
           data.is_mvno,

    // Tier 3: Acceptable (Mobile-capable VoIP)
    tier3: data.line_type === 'voip' &&
           data.voip_type === 'mobile_app' &&
           data.voip_sms_capable,

    // Block: Not suitable for SMS
    block: data.line_type === 'fixed_line' ||
           data.line_type === 'premium_rate' ||
           data.line_type === 'unknown' ||
           (data.line_type === 'voip' && !data.voip_sms_capable)
  };

  // Determine recommendation
  let recommendation = 'block';
  if (classification.tier1) recommendation = 'tier1';
  else if (classification.tier2) recommendation = 'tier2';
  else if (classification.tier3) recommendation = 'tier3';

  return {
    phone: phoneNumber,
    lineType: data.line_type,
    carrier: data.carrier_name,
    isMvno: data.is_mvno,
    recommendation,
    smsCapable: recommendation !== 'block',
    estimatedDeliveryRate: {
      tier1: 0.98,
      tier2: 0.94,
      tier3: 0.85,
      block: 0
    }[recommendation]
  };
}

// Bulk Mobile Line Verification for CSV Lists
class MobileLineFilter {
  constructor(apiKey, options = {}) {
    this.apiKey = apiKey;
    this.batchSize = options.batchSize || 100;
    this.rateLimitMs = options.rateLimitMs || 100;
    this.baseUrl = 'https://api.phone-check.app/v1/validate-batch';
  }

  async processList(phoneNumbers, onProgress) {
    const results = {
      mobile: [],
      landline: [],
      voip: [],
      invalid: [],
      stats: { processed: 0, total: phoneNumbers.length }
    };

    // Process in batches
    for (let i = 0; i < phoneNumbers.length; i += this.batchSize) {
      const batch = phoneNumbers.slice(i, i + this.batchSize);

      const response = await fetch(this.baseUrl, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': 'Bearer ' + this.apiKey
        },
        body: JSON.stringify({
          phones: batch,
          include_line_type: true,
          include_carrier: true
        })
      });

      const data = await response.json();

      // Categorize results
      for (const result of data.results) {
        const entry = {
          phone: result.phone,
          lineType: result.line_type,
          carrier: result.carrier_name,
          country: result.country_code
        };

        switch (result.line_type) {
          case 'mobile':
            results.mobile.push(entry);
            break;
          case 'fixed_line':
            results.landline.push(entry);
            break;
          case 'voip':
            results.voip.push(entry);
            break;
          default:
            results.invalid.push(entry);
        }

        results.stats.processed++;
      }

      // Progress callback
      if (onProgress) {
        onProgress(results.stats);
      }

      // Rate limiting
      if (i + this.batchSize < phoneNumbers.length) {
        await new Promise(r => setTimeout(r, this.rateLimitMs));
      }
    }

    // Calculate savings
    results.stats.savings = {
      totalMessages: phoneNumbers.length,
      mobileMessages: results.mobile.length,
      filteredMessages: results.landline.length + results.invalid.length,
      costPerSms: 0.03,
      savedAmount: ((results.landline.length + results.invalid.length) * 0.03).toFixed(2),
      campaignSavingsPercent: ((results.landline.length + results.invalid.length) / phoneNumbers.length * 100).toFixed(1)
    };

    return results;
  }
}