What is LRN lookup used for?

LRN (Local Routing Number) lookup identifies the correct network routing for phone numbers, especially ported numbers. Essential for VoIP providers, carriers, and telecom companies to ensure proper call delivery and avoid routing fees.

Why is LRN lookup important for telecom?

LRN lookup prevents misrouted calls and reduces interconnect costs. When numbers are ported between carriers, the LRN helps identify the current serving carrier, ensuring calls reach their destination efficiently.

How accurate is your LRN database?

Our LRN database maintains 99.9% accuracy with real-time updates from telecom carriers. We sync with official porting databases multiple times daily to ensure you have the most current routing information.

LRN API - Real-Time Local Routing Number Lookup

What is LRN?

The LRN (Local Routing Number) API provides fast routing number lookup for phone numbers. Perfect for high-volume applications that need routing information without additional data.

API Features

Ultra-fast Performance: Optimized for high-volume processing
Routing Information: Get LRN data for call routing
Enhanced Data: Optional carrier and location details
Messaging Integration: Optional messaging provider data
High Availability: 99.9% uptime guarantee

Authentication

All API requests require authentication using your API key. Include your API key in the request headers:

Authorization: Bearer YOUR_API_KEY

Don't have an API key? Get your API key here.

API Methods

REST Endpoint

POST https://verirouteintel.com/api/v1/lrn

Request Body (Full Response)

{
  "phone_number": "13364086644",
  "include_enhanced_lrn": true,
  "messaging_lookup": true
}

Request Body (LRN-Only Mode - Fastest)

{
  "phone_number": "13364086644",
  "lrn_only": true
}

Response

{
  "lrn": "13364086644",
  "lrn_activated_at": "2021-09-01T00:00:00+00:00",
  "enhanced_lrn_data": {
    "carrier": "Verizon",
    "carrier_type": "WRS",
    "city": "New York",
    "zip_code": "10001",
    "county": "New York",
    "timezone": "-0500",
    "state": "NY",
    "rate_center": "NYC",
    "lata": "132",
    "ocn": "921"
  },
  "messaging": {
    "provider": "Verizon Wireless",
    "enabled": true,
    "country": "US",
    "country_code": "1",
    "reference_id": "MSG-abc123"
  }
}

Bulk LRN Lookup

Process up to 1000 phone numbers in a single request with automatic deduplication and two-phase billing.

POST https://verirouteintel.com/api/v1/lrn/bulk

Request Body

{
  "phone_numbers": ["13364086644", "19494600638", "13364086644"],
  "include_enhanced": true,
  "include_messaging": false
}

Response

{
  "job_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "results": [
    {
      "phone_number": "13364086644",
      "e164_phone": "+13364086644",
      "lrn": "13364086644",
      "input_indices": [0, 2],
      "status": "success",
      "enhanced_lrn": { ... }
    },
    {
      "phone_number": "19494600638",
      "e164_phone": "+19494600638",
      "lrn": "19494600638",
      "input_indices": [1],
      "status": "success",
      "enhanced_lrn": { ... }
    }
  ],
  "summary": {
    "submitted": 3,
    "unique": 2,
    "duplicates_removed": 1,
    "succeeded": 2,
    "failed": 0,
    "from_cache": 0,
    "invalid_count": 0,
    "breakdown": {
      "success": 2,
      "failed": 0,
      "invalid_format": 0
    }
  },
  "billing": {
    "estimated_cost": 0.02,
    "actual_cost": 0.02,
    "savings_from_deduplication": 0.01,
    "per_lookup_rate": 0.01
  },
  "timing": {
    "submitted_at": "2025-12-20T10:30:00Z",
    "started_at": "2025-12-20T10:30:00Z",
    "completed_at": "2025-12-20T10:30:01Z",
    "duration_ms": 1234
  }
}

Key Features

Automatic Deduplication: Duplicate phone numbers are detected and only charged once. The input_indices field shows which positions in your input array map to each result.
Two-Phase Billing: Balance is reserved before processing and settled after completion. Failed lookups are not charged.
Full Transparency: Response includes detailed summary, billing breakdown, and timing information.
Job Tracking: Each bulk request gets a unique job_id for audit and support purposes.

Parameters

Parameter	Type	Required	Description
`phone_number` / `phoneNumber`	string	Yes	The phone number to lookup (11-digit US number)
`include_enhanced_lrn` / `includeEnhancedLrn`	boolean	No	Include enhanced LRN data (default: false)
`messaging_lookup` / `includeMessaging`	boolean	No	Include messaging provider data (default: false)
`include_cnam` / `includeCnam`	boolean	No	Include CNAM (Caller ID Name) data in the response (default: false). Additional charge applies.
`include_trust` / `includeTrust`	boolean	No	Include trust/reputation data with reputation_score and trust_level in the response (default: false). Additional charge applies.
`lrn_only`	boolean	No	Ultra-fast mode: returns only phone_number and lrn, skips caching for fastest response (default: false)

Response Format

⭐ Exclusive: the lrn_activated_at field

Most lookup APIs tell you a number's current carrier. We also tell you when it last ported there. Every phone number is born on an original carrier; when it's ported, the lrn_activated_at timestamp records the date of that most recent port.

Example: a number issued by CenturyLink (Lumen) that the subscriber later ports to AT&T Wireless returns carrier: "AT&T Wireless" with an lrn_activated_at of the port date. A number that has never left its original carrier returns no lrn_activated_at (or its original activation date).

This is the strongest signal for SIM-swap / account-takeover detection (a port in the last 30 days warrants step-up auth), number-reassignment checks, and carrier-tenure trust scoring. Included free with every LRN lookup — no extra call, no extra charge. See the LRN Activation Date feature page.

Note: The lrn_activated_at field is optional and may not be present if the activation date is unavailable (e.g., a number that has never been ported, or where the carrier does not expose the date).

LRN-Only Mode (Fastest)

When lrn_only=true, the API returns only the LRN for maximum performance:

{
  "lrn": "13364086644"
}

Standard LRN Lookup

{
  "lrn": "13364086644",
  "phone_number": "13364086644",
  "lrn_activated_at": "2021-09-01T00:00:00+00:00"
}

Standard LRN Lookup (when activation date unavailable)

{
  "lrn": "13364086644",
  "phone_number": "13364086644"
}

Enhanced LRN Lookup

{
  "lrn": "13364086644",
  "phone_number": "13364086644",
  "lrn_activated_at": "2021-09-01T00:00:00+00:00",
  "enhanced_lrn": {
    "carrier": "Verizon Wireless",
    "carrier_type": "WIRELESS",
    "city": "Clemmons",
    "state": "NC",
    "zip_code": "27012",
    "county": "Forsyth",
    "country_code": "US",
    "timezone": "-0500",
    "rate_center": "WINSTN SAL",
    "lata": "424",
    "ocn": "6324"
  }
}

LRN with Messaging

{
  "lrn": "13364086644",
  "phone_number": "13364086644",
  "lrn_activated_at": "2021-09-01T00:00:00+00:00",
  "messaging": {
    "provider": "Verizon Wireless",
    "enabled": true,
    "country": "US",
    "country_code": "1",
    "reference_id": "MSG-xyz"
  }
}

LRN with CNAM

When include_cnam=true, the response includes caller ID name information:

{
  "lrn": "13364086644",
  "phone_number": "13364086644",
  "lrn_activated_at": "2021-09-01T00:00:00+00:00",
  "cnam": "VERIZON WIRELESS"
}

LRN with Trust Data

When include_trust=true, the response includes trust/reputation information:

{
  "lrn": "13364086644",
  "phone_number": "13364086644",
  "lrn_activated_at": "2021-09-01T00:00:00+00:00",
  "trust": {
    "is_spam": false,
    "is_robocall": false,
    "is_scam": false,
    "spam_type": "NONE",
    "reputation_score": 85,
    "trust_level": "high",
    "last_updated": "2026-01-18T15:30:00Z"
  }
}

Full Response (All Options Enabled)

When all include options are enabled:

{
  "lrn": "13364086644",
  "phone_number": "13364086644",
  "lrn_activated_at": "2021-09-01T00:00:00+00:00",
  "enhanced_lrn": {
    "carrier": "Verizon Wireless",
    "carrier_type": "WIRELESS",
    "city": "Clemmons",
    "state": "NC",
    "zip_code": "27012",
    "county": "Forsyth",
    "timezone": "-0500"
  },
  "messaging": {
    "provider": "Verizon Wireless",
    "enabled": true,
    "country": "US"
  },
  "cnam": "VERIZON WIRELESS",
  "trust": {
    "is_spam": false,
    "is_robocall": false,
    "is_scam": false,
    "spam_type": "NONE",
    "reputation_score": 85,
    "trust_level": "high",
    "last_updated": "2026-01-18T15:30:00Z"
  }
}

Trust Level Values

The trust_level field is derived from the reputation_score:

high: reputation_score >= 70 (trusted number)
medium: reputation_score 40-69 (some concerns)
low: reputation_score < 40 (likely spam/scam)

Integration Examples

cURL - REST API

curl -X POST https://verirouteintel.com/api/v1/lrn \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"phone_number": "13364086644", "include_enhanced_lrn": true, "messaging_lookup": true}'

Python - REST API

import requests

url = "https://verirouteintel.com/api/v1/lrn"
headers = {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json"
}
data = {
    "phone_number": "13364086644",
    "include_enhanced_lrn": True,
    "messaging_lookup": True
}

response = requests.post(url, headers=headers, json=data)
result = response.json()
print(result)

Error Handling

The API returns standard HTTP status codes and detailed error messages:

{
  "error": "Invalid phone number format",
  "details": "Phone number must be 11 digits starting with 1"
}

Rate Limits

API requests are limited to:

All requests: 200 rps per minute
Rate limits are per API key
Upgrade your plan for higher limits

Rate limit headers are included in all responses:

X-RateLimit-Limit: 200
X-RateLimit-Remaining: 99
X-RateLimit-Reset: 60

429 Too Many Requests

When rate limits are exceeded, the API returns a 429 status code:

{
  "error": "Rate limit exceeded",
  "message": "Too many requests. Please wait before making another request.",
  "retry_after": 60
}

Pricing

Our LRN API uses a simple pay-as-you-go pricing model:

Always Free Tier: 10 free LRN/Enhanced LRN lookups per month
Pay-per-use: Competitive per-lookup pricing after wallet funding
No subscriptions: No recurring charges or auto-refill
Enterprise: Custom pricing for high-volume usage

View detailed pricing →

FAQs

What is an LRN and why is it important?

A Local Routing Number (LRN) is a unique identifier used in the North American telephone system to route calls to the correct carrier when a phone number has been ported.

What does lrn_activated_at represent?

The lrn_activated_at field indicates when the LRN was last activated or ported. This timestamp is returned in ISO 8601 format (e.g., "2021-09-01T00:00:00+00:00") and helps you determine the last time a phone number was ported to a different carrier. This field may be null if the activation date is not available.

How accurate is the LRN data?

Our LRN database is updated in real-time and maintains 99.9% accuracy for U.S. phone numbers.

Can I get enhanced carrier information?

Yes, by setting the include_enhanced_lrn parameter to true, you'll receive additional carrier, location, and routing details.

LRN API – U.S. Local Routing Number Lookup

What is LRN?

API Features

Authentication

API Methods

REST Endpoint

Request Body (Full Response)

Request Body (LRN-Only Mode - Fastest)

Response

Bulk LRN Lookup

Request Body

Response

Key Features

Parameters

Response Format

LRN-Only Mode (Fastest)

Standard LRN Lookup

Standard LRN Lookup (when activation date unavailable)

Enhanced LRN Lookup

LRN with Messaging

LRN with CNAM

LRN with Trust Data

Full Response (All Options Enabled)

Trust Level Values

Integration Examples

cURL - REST API

Python - REST API

Error Handling

Rate Limits

429 Too Many Requests

Pricing

FAQs

What is an LRN and why is it important?

What does lrn_activated_at represent?

How accurate is the LRN data?

Can I get enhanced carrier information?