NumLookup API for phone intelligence

NumLookup Reverse Phone Lookup API

Add phone number intelligence directly into your product. Identify callers, enrich phone records, reduce junk signups, and make smarter decisions with a fast, developer-friendly reverse phone lookup API.

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Fast
Real-time lookups
Simple
REST API
Flexible
Fits any workflow
Useful
Actionable signals
POST /v1/lookup/phone
Host: api.numlookup.com
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json

{
  "phone": "+14045477779",
  "include": ["owner", "carrier", "line_type", "risk"]
}

200 OK
{
  "phone": "+1 404-547-7779",
  "is_valid": true,
  "owner_name": "John D.",
  "carrier": "Verizon Wireless",
  "line_type": "mobile",
  "location": "Atlanta, GA",
  "spam_risk": "low"
}

Why teams use it

Phone intelligence that helps you move faster and trust your data more

Whether you are reviewing leads, screening signups, or improving contact quality, NumLookup gives your product helpful information tied to a phone number.

✓

Caller identity in seconds

Look up a phone number and return useful intelligence like owner name, line type, carrier, and region when available.

✓

Built for fraud checks

Flag suspicious numbers before they create accounts, submit leads, or waste your team’s time.

✓

Cleaner deliverability

Validate and normalize numbers before you send SMS or call, so your systems work with better data.

✓

Simple developer workflow

Use one straightforward API to enrich phone numbers during signup, onboarding, lead intake, and support flows.

How it works

One request. Helpful signals back.

1. Send a phone number

Pass a number into the API during signup, lead capture, support intake, or a background workflow.

2. Retrieve phone signals

Get normalized formatting plus available identity, carrier, line type, and risk-related data points.

3. Apply business rules

Route clean leads faster, trigger manual review on suspicious numbers, or personalize your workflows.

Common use cases

Signup and onboarding
Lead verification
Fraud prevention
CRM enrichment
Call center screening
Internal review workflows
Example workflow
New signup enters phone number
↓
NumLookup API validates and enriches the number
↓
Trusted users move forward with less friction
↓
Suspicious numbers can be flagged for review

API response

Return the fields that matter to your workflow

Use the API to power internal tooling, signup checks, lead verification, and customer data enrichment with a response designed to be easy to parse.

formatted_number country_code owner_name carrier line_type location spam_risk is_valid
Sample response
{
  "phone": "+1 404-547-7779",
  "formatted_number": "+14045477779",
  "country_code": "US",
  "is_valid": true,
  "owner_name": "John D.",
  "carrier": "Verizon Wireless",
  "line_type": "mobile",
  "location": "Atlanta, GA",
  "spam_risk": "low"
}

Developer-friendly by design

Start with phone number lookup. Build smarter experiences from there.

From user verification to lead quality checks, the NumLookup Reverse Phone Lookup API helps you bring more context into every phone-based workflow.

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