Number Insight API Overview

Vonage's Number Insight API delivers real-time intelligence about the validity, reachability and roaming status of a phone number and tells you how to format the number correctly in your application. (Nexmo is now Vonage).


This document contains the following information:


  • Webhooks - you can use the Advanced API to return comprehensive data about a number to your application when it becomes available, via a webhook.

Basic, Standard and Advanced APIs

Each API level builds upon the capabilities of the previous one. For example, the Standard API includes all of the locale and formatting information from the Basic API and returns extra data about the type of number, whether it is ported and the identity of the caller (US only). The Advanced API provides the most comprehensive data. It includes everything that is available in the Basic and Standard APIs and adds roaming and reachability information.

Unlike the Basic and Standard APIs which are synchronous APIs, the Advanced API is intended to be used asynchronously.

Typical use cases

  • Basic API: Discovering which country a number belongs to and using the information to format the number correctly.
  • Standard API: Determining whether the number is a landline or mobile number (to choose between voice and SMS contact) and blocking virtual numbers.
  • Advanced API: Ascertaining the risk associated with a number.

Feature comparison

Feature Basic Standard Advanced
Number format and origin
Network type
Carrier and country
Reachability (not available in the US)
Roaming status
Roaming carrier and country
US number caller name and type

Check the legislation in your country to ensure that you are allowed to save user roaming information.

Getting Started

This example shows you how to use the Nexmo CLI to access the Number Insight Basic API and display information about a number.

For examples of how to use Basic, Standard and Advanced Number Insight with curl and the developer SDKs see the Code Snippets.

Before you begin:

Install and set up the Nexmo CLI

$ npm install -g nexmo-cli

Note: Depending on your user permissions, you might need to prefix the above command with sudo.

Use your VONAGE_API_KEY and VONAGE_API_SECRET from the dashboard getting started page to set up the Nexmo CLI with your credentials:


Execute a Number Insight API Basic lookup

Execute the example command shown below, replacing the phone number with one that you want information about:

nexmo insight:basic 447700900000

View the response

The Basic API response lists the number together with the country the number is located in. For example:

447700900000 | GB

Use the --verbose flag (or -v) to see everything that the Basic API response contains:

$ nexmo insight:basic --verbose 447700900000





07700 900000



United Kingdom



Code Snippets

Use Cases