LRN Lookup API
Get Local Routing Number (LRN) data for accurate phone number routing and portability information.
How LRN Works
Local Routing Number (LRN) lookup provides essential routing information for phone numbers, including portability data and enhanced network details for accurate call routing and billing.
Key Features:
- Real-time LRN data retrieval
- Number portability detection
- LRN Activation Date - Know when a number was ported (FREE with every lookup)
- Enhanced LRN data with carrier details
- Messaging provider integration
- High-accuracy routing information
- Bulk lookup capabilities
The activated_at Timestamp
Every VRI LRN response includes activated_at — a timestamp recording when the number was last ported. This field is exclusive to VRI and unavailable from any other LRN provider. For fraud prevention teams, activated_at is the earliest signal of a SIM swap or line hijacking: a number ported minutes before a high-value transaction is a strong indicator of porting fraud.
Use Cases:
- Call routing optimization
- Billing and cost management
- Number portability verification
- Carrier identification
- Fraud prevention and security
- Telecom infrastructure planning
Carrier Routing
Our LRN lookup service provides comprehensive carrier routing information to optimize call delivery and ensure accurate billing. Access real-time data for efficient network management and enhanced customer experience.
Stop SIM Swap Fraud Before It Happens
LRN Activation Date monitoring is your first line of defense against the fastest-growing fraud vector in telecom.
How it works: When a number is recently ported (LRN activation within 24-72 hours), it's a red flag for potential SIM swap fraud. Our API returns this data with every lookup so you can flag high-risk transactions in real-time.
The activated_at Field — Know When a Number Was Ported
Every VRI LRN response includes lrn_activated_at — the timestamp of when the number was last activated on its current carrier network. No extra charge, no extra query.
Use it to flag numbers ported within the last 24–72 hours, the clearest real-time signal for SIM swap and account-takeover fraud.
Example Response — activated_at in LRN Lookup
GET /api/v1/lrn?phone_number=+15551234567&include_enhanced_lrn=true
Response:
{
"lrn": "+15551234000",
"phone_number": "+15551234567",
"lrn_activated_at": "2026-04-29T14:22:05+00:00",
"ported": true,
"enhanced_lrn_data": {
"carrier": "T-Mobile",
"carrier_type": "mobile",
"state": "CA"
}
}
Fraud signal: lrn_activated_at is within the past 72 hours and ported is true → treat as high-risk for account authentication flows.
LRN Lookup — Frequently Asked Questions
What is activated_at in an LRN lookup?
The lrn_activated_at field returns the ISO 8601 timestamp of when a phone number was last activated on its current carrier network — i.e., when the most recent number port completed. It is included free with every LRN lookup and is the primary signal used to detect recent SIM swap activity.
What is a phone number activation date?
A phone number activation date (also called the LRN activation timestamp) is the date and time a number became active on its current carrier after a port or initial activation. Unlike the original issue date, this timestamp updates every time the number is ported, making it a live fraud-risk indicator rather than a static historical fact.
How do I use the LRN activation timestamp for fraud detection?
Compare lrn_activated_at against your transaction or authentication timestamp. If the number was ported within the prior 24–72 hours, treat it as elevated fraud risk — especially for SMS-based OTP flows, password resets, or high-value transactions. Most SIM swap attacks show a port timestamp within hours of the fraudulent access attempt.
Does VRI charge extra for the activated_at field?
No. lrn_activated_at is returned in every LRN response at no additional cost. You pay the standard LRN lookup rate ($0.0005 per query) and get the activation timestamp, ported status, carrier name, carrier type, and full enhanced LRN data in a single API call.
Is there a difference between LRN and carrier lookup?
Yes. A carrier lookup identifies the current serving carrier of a phone number. An LRN lookup returns the Local Routing Number used to route calls to that number plus — with enhanced data — the carrier name, carrier type, rate center, LATA, OCN, and activation timestamp. VRI bundles carrier lookup into every LRN query at no extra charge, making separate carrier-lookup calls unnecessary.
What is LRN (Local Routing Number) and why does it matter?
LRN stands for Local Routing Number — a 10-digit code assigned by carriers to route calls correctly across the public switched telephone network. When a subscriber ports their number to a new carrier, the LRN changes to reflect the new routing destination. Accurate LRN data ensures calls connect correctly and prevents misdirected traffic, reducing both failed calls and unnecessary termination costs.
How accurate is VRI Enhanced LRN data?
VRI sources LRN data directly from carrier-grade databases updated in near real time. Our Enhanced LRN product returns not just the routing number but also associated carrier, line type, and the exclusive activated_at port timestamp — fields absent from commodity LRN feeds. Accuracy is validated continuously against live number portability events, not periodic bulk refreshes.
How does VRI LRN pricing compare to other providers?
VRI LRN is priced at $0.0005 per lookup — roughly 10× cheaper than Twilio's ~$0.005 LRN lookup and 3× cheaper than Telnyx's ~$0.0015. There is no minimum commit, no monthly floor, and no tiered pricing that requires a sales call to unlock. You pay per lookup; invalid numbers are not billed.
Can I use VRI LRN with my existing telecom platform?
Yes. VRI exposes both a REST API and a GraphQL endpoint with standard JSON responses. If your platform can make an HTTP request, it can query VRI LRN data. Most integrations go live within a day. A free tier of 10 free lookups lets you validate the integration before committing to any usage volume — no credit card required. Full documentation is at our API docs.
Access LRN data through our powerful GraphQL API for flexible queries and efficient data fetching. Perfect for modern applications requiring precise data control.
Explore GraphQL →Need high-volume access or custom features? Our Enterprise plans offer dedicated support, competitive rates, and SLA guarantees.
Contact Sales →Integration
GET /api/v1/lrn?phone_number=+15551234567&include_enhanced_lrn=true
Response:
{
"lrn": "+15551234000",
"phone_number": "+15551234567",
"lrn_activated_at": "2021-09-01T00:00:00+00:00",
"enhanced_lrn_data": {
"carrier": "Verizon Wireless",
"carrier_type": "mobile",
"city": "New York",
"state": "NY",
"zip_code": "10001",
"county": "New York",
"timezone": "-0500",
"rate_center": "NYC",
"lata": "132",
"ocn": "921"
}
}GraphQL Query
query {
lookupLrn(
phoneNumber: "+15551234567"
includeEnhanced: true
includeMessaging: false
) {
number
lrn
enhanced {
carrier
carrier_type
city
state
zip_code
county
timezone
rate_center
lata
ocn
}
}
}