Number lookup API
Get in the know with number lookup
The more you know about numbers, the more effective your communications will be. Telnyx Number Lookup allows our customers to find the carrier and caller information behind each phone number. This information can be used to help increase outbound calling productivity and outbound message deliverability, plus protect your business against spam and fraudulent inbound calls.
Don’t leave your communications to chance
Understand who you are communicating with for enhanced productivity and deliverability.
Real-time CNAM data
Look up the nationally-maintained CNAM database to attach a caller ID name to your incoming calls–even if the other party has never called you before.
Detailed carrier information
Know what carrier a number is attached to in order to understand cost and deliverability.
Access customer insights
Know who you are calling with detailed information about the person behind the phone number. Protect your business against spam and fraud with Caller ID name info.
BENEFITS
Send messages that deliver
Split landline and mobile numbers programmatically, and check carrier information to guarantee deliverability.
APIs
To streamline your processes
Increase security
When you know a customer can receive SMS, enable two-factor authentication (2FA) to verify their credentials to keep both your data and their data safe.
2FA
To keep data safe
Number Lookup vs Reverse Phone Lookup
Consumer reverse phone lookup tools like Whitepages answer one question for one person: who called me? You type in a number and get a name, maybe an address, pulled from public records.
Number Lookup solves a different problem. It's a phone number carrier lookup API built for businesses that need to validate numbers at scale - thousands or millions at a time, programmatically. Instead of a name from public records, you get authoritative network data: the current carrier, whether the number is mobile or landline, its routing number, and registered caller ID (CNAM lookup).
The distinction matters because the data sources differ. Reverse phone lookup tools scrape public records that go stale. Number Lookup queries live telecom databases - including HLR lookup for mobile status - so the answer reflects the number's real-time status, including recent ports between carriers.
If you're checking one number out of curiosity, use a consumer tool. If your application needs phone number validation or caller ID lookup at scale, use the API.
What you can build with Number Lookup API
From SMS deliverability to fraud prevention, number lookup powers the decisions your application makes about every phone number.
SMS deliverability
Landlines can't receive texts, and messages sent to them still cost money. Running a lookup before sending confirms the number is mobile and identifies the carrier, so your messages reach real inboxes.
Fraud & spam prevention
VoIP and virtual numbers are the tool of choice for fake signups and SMS pumping fraud. Lookup flags line type in real time, letting you block or challenge risky numbers before they enter your system.
Lead scoring
A disconnected or invalid number is a dead lead. Validate numbers at the point of capture to keep your CRM clean and your sales team focused on contacts that answer.
Two-factor authentication
Sending OTP codes to unverifiable numbers creates friction and cost. Phone number verification via Lookup confirms a number can receive the code before you send it, improving completion rates.
Call routing
The LRN reveals which switch actually serves a number after porting. Use it to route calls efficiently and avoid misdirected traffic on your voice infrastructure.
Bulk number lookup
Need to clean a database of millions of numbers? The API handles batch phone number validation at throughput rates that consumer tools can't match.
What every lookup returns
Request only the data types you want and pay per dip, not per field. Responses return in milliseconds over REST.
Carrier name
The network currently serving the number, accurate after porting. HLR lookup confirms the live carrier for mobile numbers.
Line type intelligence
Mobile, landline, or VoIP. Know what the number can do — landlines can't receive SMS, VoIP numbers are higher fraud risk.
LRN lookup API
Location Routing Number identifying the serving switch for routing decisions. Know who actually services a number today, not who originally issued it.
CNAM lookup API
The registered caller ID name associated with the number. Attach a caller ID name to incoming calls even if the caller has never called you before.
Ported status
Whether the number has moved carriers, and when. Ported number lookup reflects the actual serving carrier today, not the original carrier.
E.164 format & MCC/MNC
All inputs in E.164 format for consistent processing. Mobile Country Code (MCC) and Mobile Network Code (MNC) for international carrier identification.
RESOURCES
Start building
Our code is your code.
Retrieving caller name and carrier
Number lookup and CNAM allow Telnyx users to look up a phone number and retrieve information about the phone number.
Increase lead conversions with number lookup
Implementing real-time intelligence into your inbound sales is the fastest way to start generating value with number lookup.
SMS marketing with Telnyx
Three important features when choosing an SMS provider are pricing, global reach and being able to stay true to your brand.
SOLUTIONS
What can you build with Telnyx Lookup API?
Call tracking
Increase campaign ROI with higher conversion rates.
Learn more
Contact center
Improve call outcomes with instant customer context.
Learn more
SMS marketing
Engage customers with targeted messages and personalized offers.
Learn more
Two-factor authentication
Use SMS to verify customer credentials and keep your data safe.
Learn more
FAQ
Resources, Docs, Support
Number Lookup hub
Number Lookup using Telnyx API | Telnyx
Lookup a phone number and retrieve information. Start building on Telnyx today.
Account | Telnyx
The Account API allows users to manage addresses and billing info associated with their account.
LRN lookup using HTTP API V1 | Telnyx
Uses HTTP to retrieve the local routing number information (LRN).
Using an HTTP Request API V1 | Telnyx
Returns the caller information (if found) for a telephone number.
[eBook] Build Better Customer Experience with Number Lookup
Learn how to leverage next-generation number lookup tools to incorporate rich data about your incoming callers to your customer experience.
Use Number Lookup Tools to Increase Lead Conversions
Learn how to leverage Number Lookup tools to convert more leads and increase sales. Try it out today!
Smart IVR & Conversational AI Are Better With Number Lookup
Learn how to improve your interactive voice response system by using Number Lookup tools to feed rich customer context to your conversational AI.
Automated International Number Search and Order
Streamline your international number search and order process with our latest API.
Here’s how to check if your number can be ported
Phone number portability check in bulk. Looking for a port eligibility tool that can let you easily check up to 2,500 numbers at a time?
5 Advanced Phone Number Searching Examples with Telnyx
Telnyx offers the most powerful number search and purchasing APIs and portals on the market. Check out our demonstration of advanced searches.
Using Telco Data for Lead Scoring - powered by Telnyx
Telco data can also be used to establish context around incoming calls or verify contact information for inbound leads.
Types of phone numbers and their business use cases
Discover different types of phone numbers, their benefits, and which number is the best fit for your use case.
Telnyx Blog | CPaas & UCaaS Resources
Find data-driven research, comprehensive guides and all things SIP trunking, voice and SMS APIs, wireless and more.
Global Numbers - The Real Facts You Need
Instantly provision local, national and toll-free numbers globally.Make & receive calls or send SMS globally with the API built for reliable communications
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Your Number Lookup Guide | Telnyx Help Center
This article will explain the Number Lookup interface on the Telnyx Mission Control portal
The Rate Sheet and LRN explained | Telnyx Help Center
Why a supposed Rate Sheet price may not match the actual call price or why the rate limit may trigger earlier than expected.
Telnyx Tech Specs | Telnyx Help Center
Here you will find out key tech specs at Telnyx and what they mean for our service.
Number Features | Telnyx Help Center
Discover Telnyx's number features: Voicemail, Call Forwarding, Caller ID, and more.
Search and Buy Numbers | Telnyx Help Center
This article describers to process of obtaining numbers through Telnyx
The Rate Sheet and LRN explained | Telnyx Help Center
Why a supposed Rate Sheet price may not match the actual call price or why the rate limit may trigger earlier than expected.
Embedded Number Search (Provisioning)
Build number searching into your application with ease using Telnyx. Our number lookup API is fast, and priced competitively.
Caller ID Management - Integrate with Telnyx
Use Telnyx's Caller ID management tools to route and prioritize calls and customize conversations with customers.