Allow calls from selected countries#

Scenario: A company wants to accept calls only from callers whose numbers begin with the UK country code 44 or Germany’s country code 49, while blocking all other inbound calls.

Step 1: Create a Number List#

  1. Go to Voice > Inbound Trunks and open the Number Lists tab.

  2. Click Create New and enter a Friendly name (e.g., UK and DE 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. 1. Creating a Number List for Country-Based Filtering#

Step 2: Add the allowed prefixes#

Enter the prefixes in the format used for matching. Country-code prefixes match only calling numbers in E.164 format without a leading +, such as 442071234567. A calling number such as +442071234567 does not start with 44. For a SIP trunk, this example requires CLI Format set to E.164 and no CLI Prefix.

  1. Click the Actions 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.

With Prefix match, 44 matches every calling number that starts with 44, such as 442071234567, and 49 matches every calling number that starts with 49.

Adding Country Codes to Allow Calls

Fig. 2. Adding Country Codes to Allow Calls#

Step 3: Assign the Number List to a trunk#

Assign the Number List to the inbound SIP or PSTN trunk that receives these calls so the call filtering rules take effect. Select it in the trunk’s CLI Number List field on the Number Translations tab. For the steps, see Assign a Number List to a Trunk.

Calling numbers beginning with 44 or 49 are allowed. All other calls are rejected.