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updatedAt: 2026-07-20T18:11:19.000Z
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# SENTRY Call Blocking

SENTRY Call Blocking ensures only legitimate business calls are delivered to customers, while spoofed or unauthenticated calls are blocked before reaching the end-user’s device. This guide walks you through step-by-step details on how to start using SENTRY Call Blocking.

## Pre-requisites

* A signed agreement is required prior to rendering service. To initiate an agreement, connect with one of our [sales representatives](https://firstorion.com/contact-us).
* Create or log in to your [Customer Portal](https://portal.firstorion.com/app/landing#/start)   account
* Upon [Registering](https://developer.firstorion.com/firstorion-public/docs/business-registration-api-guide)  the phone numbers that will be branded, the business will be Vetted and Approved by First Orion. Your business must meet [vetting requirements](https://support.firstorionenterprise.com/hc/en-us/articles/41080138699917-What-are-the-Business-vetting-requirements-for-vetting)  to begin branding.
* Generate [API keys](https://developer.firstorion.com/firstorion-public/docs/api-credentials)  from the Customer Portal
* Understanding of your calling platform & the environment to integrate
* Configure [Automated Number Vetting](https://developer.firstorion.com/firstorion-public/docs/acc)  process for monthly vetting of telephone numbers.

## Integration

* Complete the [Call Authentication Integration](https://developer.firstorion.com/firstorion-public/docs/call-authentication-2)  to get started
* Complete the [Automated Number Vetting](https://developer.firstorion.com/firstorion-public/docs/acc)  Configuration for telephone number vetting

## Program Creation

* Review [Branded Calling Content Policies](https://support.firstorionenterprise.com/hc/en-us/articles/14396781228429-Policy-for-Branded-Calling) and [Display Name Guidelines](https://developer.firstorion.com/firstorion-public/docs/custom-callername-guidelines)  to ensure your display name meets the policy for branding.
* Create a SENTRY Call Blocking program
  * Creating programs via [API](https://developer.firstorion.com/firstorion-public/docs/create-programs-via-api)
  * Creating program via [Customer Portal](https://support.firstorionenterprise.com/hc/en-us/articles/26432295185165-How-do-I-create-a-program-in-the-Customer-Portal)
* Monitor and verify display details to ensure proper setup
  * **T-Mobile:** SENTRY is implemented after TNs are vetted and approved.
  * **Verizon:** SENTRY is implemented after the TNs are vetted, approved and have completed a 14-day blocking period on the T-Mobile network.
  * **AT\&T:** SENTRY is implemented after the TNs are vetted, approved and have completed a 14-day blocking period on the T-Mobile network

*Ongoing, it is critical to notify your FO Account Team when you make any changes to your programs (adding numbers, changing displays, changing logos, etc.) to ensure proper provisioning takes place.*