Reject Incoming Calls Using .NET


When you don’t want to receive incoming calls on your Plivo numbers, follow the instructions in this guide to create an application to reject them.

You can reject incoming calls either by using our PHLO visual workflow builder or our APIs and XML documents. Follow the instructions in one of the tabs below.

You can create and deploy a PHLO to reject incoming calls with a few clicks on the PHLO canvas, without writing a single line of code.

How it works

When you receive a call on a voice-enabled Plivo number, you can control the call flow by associating a PHLO application to that Plivo number. Plivo will fetch the PHLO associated with the number and expect valid instructions via PHLO to handle the call.

Inbound Call Flow


To get started, you need a Plivo account — sign up with your work email address if you don’t have one already. To receive incoming calls, you must have a voice-enabled Plivo phone number. You can rent numbers from the Numbers page of the Plivo console, or by using the Numbers API.

Create the PHLO

To create a PHLO, visit the PHLO page of the Plivo console. If this is your first PHLO, the PHLO page will be empty.

Create a PHLO to reject incoming calls

  • Click Create New PHLO.
  • In the Choose your use case pop-up, click Build my own. The PHLO canvas will appear with the Start node.
    Note: The Start node is the starting point of any PHLO. It lets you trigger a PHLO to start upon one of three actions: incoming SMS message, incoming call, or API request.
  • From the list of components, on the left hand side, drag and drop the Hangup component onto the canvas. When a component is placed on the canvas it becomes a node.
  • Draw a line to connect the Start node’s Incoming Call trigger state to the Hangup node.
  • Click Validate to save the configuration.
  • Give the PHLO a name by clicking in the upper left, then click Save.

Assign the PHLO to a Plivo number

Once you have created and configured your PHLO, assign your PHLO to a Plivo number.

  1. On the Numbers page of the console, under Your Numbers, click the phone number you want to use for the PHLO.
  2. In the Number Configuration box, select PHLO from the Application Type drop-down.
  3. From the PHLO Name drop-down, select the PHLO you want to use with the number, then click Update Number.

Assign PHLO to a Plivo number


You can now make a call to your Plivo phone number and see that calls are rejected.

For more information about creating a PHLO application, see the PHLO Getting Started guide. For information on components and their variables, see the PHLO Components Library.

Here’s how to use a Plivo XML document that rejects incoming calls on a Plivo number.

How it works

Inbound Call Flow

Plivo requests an answer URL when it answers the call (step 2) and expects the file at that address to hold a valid XML response from the application with instructions on how to handle the call. In this example, when an incoming call is received, Plivo rejects the call using the Hangup XML element.


To get started, you need a Plivo account — sign up with your work email address if you don’t have one already. You must have a voice-enabled Plivo phone number to receive incoming calls; you can rent numbers from the Numbers page of the Plivo console, or by using the Numbers API. If this is your first time using Plivo APIs, follow our instructions to set up a .NET development environment and a web server and safely expose that server to the internet.

Create an MVC controller to reject incoming calls

In Visual Studio, create a new project. Use the template for Web Application (Model-View-Controller).

Create an MVC app

Give the project a name — we used Rejectcall.

Navigate to the Controllers directory in the Rejectcall project. Create a controller named RejectcallController.cs and paste into it this code.

using System;
using Plivo.XML;
using System.Collections.Generic;
using Microsoft.AspNetCore.Mvc;

namespace Rejectcall
    public class RejectcallController : Controller
        public IActionResult Index()
            Plivo.XML.Response resp = new Plivo.XML.Response();
            // Add Hangup XML Tag
            resp.AddHangup(new Dictionary<string, string>()
                {"reason","rejected"}, // Specify the reason for hangup
            var output = resp.ToString();
            return this.Content(output, "text/xml");

Create a Plivo application to reject calls

Associate the controller you created with Plivo by creating a Plivo application. Visit Voice > Applications in the Plivo console and click on Add New Application, or use Plivo’s Application API.

Give your application a name — we called ours Reject Call. Enter the server URL you want to use (for example https://<yourdomain>.com/reject_caller/) in the Answer URL field and set the method to POST. Click Create Application to save your application.

Create Application

Assign a Plivo number to your application

Navigate to the Numbers page and select the phone number you want to use for this application.

From the Application Type drop-down, select XML Application.

From the Plivo Application drop-down, select Reject Call (the name we gave the application).

Click Update Number to save.

Assign Phone Number to Reject Call


Make a call to your Plivo number using any phone. Plivo will send a request to the answer URL you provided requesting an XML response and then process the call according to the instructions in the XML document the server provides — in this case, rejecting it.