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Phone Append API

Phone AppendAPI

Append verified phone numbers using name and address data. High-quality consumer intelligence with confidence scoring and compliance-friendly enrichment.

High Quality

Match Accuracy

10 tokens

Per Request

Datazapp

Data Source

Complete Phone Enrichment Platform

Multi-field matching for maximum accuracy and reachability

Verified Carrier Intelligence

Uses trusted consumer and carrier data to append reachable phone numbers tied to provided identity fields. Datazapp-powered matching.

Carrier verification
Consumer database
Reachability checks
Identity matching

Confidence Scoring

Returns confidence indicators so you can decide when to auto-accept, review, or retry records. Quality transparency built-in.

Quality scores
Auto-accept logic
Review flags
Retry guidance

Multi-Field Matching

Name + address matching improves accuracy and reduces false positives compared to single-field lookups. Multiple signals for best results.

Multi-field logic
False positive reduction
Signal aggregation
Best match selection

Quality Insights

Provides match status and quality context to keep CRMs clean and campaigns compliant. Transparent match reasoning.

Match explanations
CRM hygiene
Compliance support
Audit trails

Phone Append Use Cases & Results

Real businesses achieving measurable improvements with phone enrichment

Lead Reachability

Append missing phone numbers on inbound leads to unlock SMS and voice outreach channels immediately.

40% more contacts
  • SMS outreach unlock
  • Voice channel access
  • Faster follow-up
  • Higher contact rates

CRM Backfill

Enrich legacy CRM records and keep sales, support, and billing teams aligned on best contact methods.

35% data completion
  • Legacy data recovery
  • Team alignment
  • Complete records
  • Better routing

Compliance-Aware Outreach

Use confidence and status metadata to respect compliance and avoid bad dials. Quality signals for safe campaigns.

50% fewer bad dials
  • Compliance support
  • Bad dial reduction
  • Status awareness
  • Safe outreach

Customer 360

Build complete customer profiles by appending verified phones. Enable omnichannel communication strategies.

45% profile completion
  • Profile completion
  • Omnichannel enablement
  • Identity resolution
  • Better personalization

Why Choose 1Lookup Phone Append?

Premium data quality with transparent pricing

Premium Consumer Database

Access to Datazapp consumer intelligence with billions of records

Confidence Scoring

Every match includes quality indicators for trust decisions

Address Normalization

Built-in address cleaning improves match rates

Transparent Pricing

Simple 10 tokens per request with no hidden fees

Simple Phone Append Integration

Enrich contacts with a single API call

POST /api/lookup
// Phone append from name and address
const response = await fetch('https://api.1lookup.io/api/lookup', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    type: 'phone-append',
    firstName: 'John',
    lastName: 'Doe',
    address: '456 Oak Avenue',
    city: 'Dallas',
    zip: '75201'
  })
})

// Response
{
  "success": true,
  "phone": "+12145551234",
  "confidence": 0.82,
  "line_type": "mobile",
  "tokens_used": 10
}

Phone Append API FAQ

Common questions about our phone enrichment service

Our phone append API requires first name, last name, street address, city, and ZIP code. The more accurate your input data, the higher the match rate.

Match rates vary based on input quality, typically 30-50% for consumer records. Each result includes confidence scores to help prioritize which numbers to use.

Phone append returns the best-matching number from our consumer database. We recommend pairing with our Phone Validation API for line type and carrier verification.

If no match is found, the API returns a no-match response. You are still charged for the lookup attempt as the database search was performed.

Technical Specifications

Token Cost

10 tokens

Data Source

Datazapp

Match Rate

30-50%

Input Fields

5 required

Confidence

Included

Response

Real-time

Start Enriching Contacts Today

Append verified phone numbers to your contact database with confidence scoring

100 free credits • Setup in 5 minutes • Premium support