Carrier Lookup API

Name: Carrier Lookup API API
Brand: Carrier Lookup API
Availability: InStock

✓ Official Vendor SpecData EnrichmentContact EnrichmentapiKey1 EndpointsREST

For Agents

Resolve a US phone number to carrier name, line type (mobile/landline/VoIP), validity, and active status via a single GET /lookup call.

Quickstart

Get started with Carrier Lookup API in minutes using your preferred integration method.

# Add to your MCP client config (Claude Desktop, Cursor, Windsurf)
{
  "jentic": {
    "url": "https://api.jentic.com/mcp",
    "auth": "oauth"
  }
}

# Then ask your agent:
"look up phone carrier"

# → Jentic returns the GET /events tool with parameter schema, agent executes.

Capabilities

What an agent can do with Carrier Lookup API API.

Identify the carrier behind a US phone number (Verizon, AT&T, T-Mobile, etc.)

Detect line type — mobile, landline, or VoIP — to inform SMS deliverability

Validate that a phone number is well-formed and reachable

Check whether a phone number is currently active

Filter out VoIP numbers in fraud-screening or signup-quality workflows

GET STARTED

Start building with Carrier Lookup API API

Explore with Jentic

View OpenAPI Document

Use Cases

Patterns agents use Carrier Lookup API API for, with concrete tasks.

★ Signup Form Phone Validation

Block signups using fake or VoIP-only phone numbers. On submission, call GET /lookup with the user-entered number; if the response says the number is invalid, inactive, or VoIP (depending on policy), reject or flag the registration. This catches throwaway numbers commonly used to evade per-account limits.

Look up the phone number a user just entered, and reject the form if line type is VoIP or active is false.

SMS Deliverability Routing

Route messages intelligently based on carrier and line type. Mobile numbers go via SMS; landlines and VoIP can be routed to voice or skipped entirely. The Carrier Lookup response provides the carrier name and line_type fields needed to make this routing decision per-recipient before submitting to a messaging gateway.

For each recipient phone number, call GET /lookup and only queue SMS messages to those returned as line_type=mobile.

CRM Contact Data Hygiene

Run a periodic enrichment pass over a CRM's phone column to mark inactive or invalid numbers and append carrier metadata. Each contact gets a single GET /lookup request, and the response fills carrier, line_type, valid, and active fields back onto the record. This avoids wasting outbound calls and SMS attempts on stale numbers.

Iterate the CRM contacts table, call /lookup for each phone, and update the record with carrier, line_type, and active status.

AI Agent Phone Verification via Jentic

Plug Carrier Lookup into an agent through Jentic so a question like 'is this number a real mobile?' becomes a single tool call. Jentic returns the GET /lookup operation schema, holds the API key in its vault, and lets any framework (LangChain, CrewAI, MCP) issue the lookup without managing the query parameter manually.

Through Jentic, look up phone number 415-555-1234 and return carrier, line_type, and active fields.

Key Endpoints

1 endpoints — carrier lookup api resolves a us phone number to its underlying carrier metadata: carrier name, line type (mobile, landline, voip), number validity, and active status.

METHOD

PATH

DESCRIPTION

GET

/lookup

Look up carrier information for a US phone number

GET

/lookup

Look up carrier information for a US phone number

Why though Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

Carrier Lookup API keys are stored encrypted in Jentic's vault. Agents receive scoped execution rights only — the key is injected into the `key` query parameter at request time and never enters the agent's prompt or chat logs.

Intent-based discovery

Agents search Jentic by intent (e.g., 'look up phone carrier' or 'detect voip number') and Jentic returns the GET /lookup operation with its input schema, so the agent supplies the right parameters without reading docs.

Time to first call

Direct Carrier Lookup integration: 1-2 hours to wire the GET /lookup endpoint, parse the response, and add basic retry handling. Through Jentic: under 10 minutes — search, load, execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Complementary

CarAPI.dev

Vehicle data API for VIN decoding and history; pairs with phone validation in marketplace fraud checks.

Use alongside Carrier Lookup in used-car-marketplace flows that verify both the vehicle and the seller's contact number.

Complementary

Careerjet Job Search API

Job search API often paired when validating candidate contact data.

Pair with Carrier Lookup when verifying candidate phone numbers from a Careerjet-sourced application.

Complementary

Careem POS API

Restaurant POS integration; phone validation supports order confirmation flows.

Use alongside Careem POS when verifying customer phone numbers attached to incoming food orders.

FAQs

Specific to using Carrier Lookup API API through Jentic.

What authentication does the Carrier Lookup API use?

Carrier Lookup uses an API key passed as the `key` query parameter on every request. Through Jentic the key is stored encrypted in the credential vault and injected into the URL at request time, so the raw key never appears in chat logs or agent prompts.

What does the Carrier Lookup API return for a phone number?

The /lookup endpoint returns the carrier name (Verizon, AT&T, T-Mobile, etc.), the line type (mobile, landline, VoIP), a validity flag indicating whether the number is well-formed, and an active flag indicating whether the line is in service. This combination supports both routing and fraud-screening use cases.

Does Carrier Lookup work for non-US phone numbers?

The API is documented as a US phone number lookup service. Coverage outside the US is not part of the OpenAPI surface; for international validation pair Carrier Lookup with another provider that covers your target geographies.

Can I use Carrier Lookup to detect VoIP numbers?

Yes. The line_type field returned by GET /lookup will indicate `voip` for VoIP numbers, `mobile` for cellular, and `landline` for fixed lines. This is the standard signal used by signup-fraud screens to filter out disposable or virtual numbers.

What are the rate limits for the Carrier Lookup API?

The OpenAPI specification does not declare numeric rate limits. Limits are tied to the plan associated with your API key — keep concurrent requests modest and back off on 429 responses. Refer to https://www.carrierlookup.com/carrier-lookup-api-integration/ for plan tiers and quotas.

How do I look up a number through Jentic?

Run `pip install jentic`, then use Jentic's search to find the lookup operation with the query "look up phone carrier", load the schema, and execute with `{"number": "4155551234"}`. Jentic calls GET /lookup with your API key from the vault and returns carrier, line_type, valid, and active fields.

Can I batch-process a list of phone numbers?

The API exposes a single GET /lookup endpoint that takes one number per call. To process a list, iterate sequentially or in modest concurrency from your application; the API does not provide a built-in bulk endpoint, so batching is the caller's responsibility.