Number List Examples & Use Cases

This section provides real-world examples of how to use Number Lists to manage inbound call filtering. You’ll learn how to add numbers and set rules to allow or block calls based on specific criteria.

With Number Lists, you can:

  • Block unwanted calls from specific numbers or prefixes.

  • Allow calls only from specific countries or regions.

  • Improve call management by filtering calls based on business needs.

Note

After setting up your Number List, make sure to assign it to an Inbound SIP Trunk so the call filtering rules take effect. See: Assign a Number List to a SIP Trunk.


Example 1: Block Calls from a Specific Prefix

Scenario: A company receives frequent spam calls from numbers starting with 1234, disrupting operations. To block these calls follow the steps:

Step 1: Create a Number List

  1. Navigate to Inbound Trunks > Number Lists.

  2. Click Create New and enter a friendly name (e.g., Spam Blocklist).

  3. Set the Mode to Prefix Match.

  4. Set the Default Action to Allow Call.

  5. Click Create.

Creating a Number List

Fig. 1. Creating a Number List

Step 2: Add the Prefix to the Number List

  1. Click the Actions button button next to the newly created Number List.

  2. Select Manage Numbers.

  3. Click Add Numbers.

  4. Enter 1234 in the input field (this blocks all calls starting with 1234) and set the action to Reject Call.

  5. Click Submit.

Adding a Prefix to Block Calls

Fig. 2. Adding a Prefix to Block Calls


Example 2: Block a Specific Phone Number

Scenario: A customer service agent reports that 15551234567 is making repeated nuisance calls and should be blocked.

Step 1: Create a Number List

  1. Navigate to Inbound Trunks > Number Lists.

  2. Click Create New and enter a friendly name (e.g., Number Blocklist).

  3. Set the Mode to Full Numbers Match.

  4. Set the Default Action to Allow Call.

  5. Click Create.

Creating a Number List for Blocking Specific Numbers

Fig. 3. Creating a Number List for Blocking Specific Numbers

Step 2: Add the Number to the List

  1. Click the Actions button button next to the Number List.

  2. Select Manage Numbers.

  3. Click Add Numbers.

  4. Enter 15551234567 in the input field and set the action to Reject Call.

  5. Click Submit.

Adding a Number to Block Calls

Fig. 4. Adding a Number to Block Calls


Example 3: Allow Calls from Specific Countries and Block Others

Scenario: A company wants to accept calls only from UK-based (44) and German (49) customers while blocking all other inbound calls.

Step 1: Create a Number List

  1. Navigate to Inbound Trunks > Number Lists.

  2. Click Create New and enter a friendly name (e.g., UK & Germany Only).

  3. Set the Mode to Prefix Match.

  4. Set the Default Action to Reject Call.

  5. Click Create.

Creating a Number List for Country-Based Filtering

Fig. 5. Creating a Number List for Country-Based Filtering

Step 2: Add the Allowed Prefixes

  1. Click the Actions button button next to the Number List.

  2. Select Manage Numbers.

  3. Click Add Numbers.

  4. Enter 44, 49 in the input field (this allows calls from the UK and Germany) and set the action to Allow Call.

  5. Click Submit.

Adding Country Codes to Allow Calls

Fig. 6. Adding Country Codes to Allow Calls


Additional Resources

Inbound Number List

Learn how to create, configure, and manage Number Lists to filter inbound calls by allowing or rejecting specific numbers or prefixes linked to SIP trunks.

Inbound Number Lists