Configuring prefix-based callback number selection

If enabled for your account, you can configure Vonage Contact Center to dynamically select a callback number based on the dialed number's prefix. You can specify as many digits as you want in the prefix. So you can select a different callback number based on the country code, area code, or even entire telephone number. 

For example, VCC can present one callback number when your agents click to dial contacts in the United Kingdom (with the prefix +44) and can present another for contacts in Spain (with the prefix +34). VCC will present the default callback number when dialing contacts with any other prefix.

Before you can configure this feature, you or your Salesforce administrator must perform the following tasks. The administrator needs to perform these tasks one time only.

  • Specify which class VCC must use to select the callback number. You specify the class in the custom settings data for your org, profile or user. Type VCCCore.SelectPresentedCLIDByNumberPrefix in the Callback Number Selector Class field. For more information about configuring custom setttings, see Configuring custom settings for optional Vonage Contact Center features in Salesforce.
  • Assign Vonage Contact Center - Auto Presented CLID user permission set to all agents and supervisors using this feature. For detailed information about this permission set, see ContactWorld Auto Presented CLID user permissions.
  • Assign the ContactWorld Supervisor permission set to any supervisor who needs to configure this feature. For detailed information about this permission set, see ContactWorld Supervisor permissions.
  • Configure sharing settings for the Vonage Prefix Mapping object if you want to restrict the access different profiles have to other profiles' records. For information about sharing settings, see Salesforce help.
  • Set the Vonage Prefix Mapping object tab to Default On for supervisors.
  • If you are using Salesforce Lightning Experience, you must add the Vonage Prefix Mappings tab to the applicable app or apps.

When your administrator has enabled the feature, you can create mappings between dialed number prefixes and callback numbers. To create a new mapping, perform the following steps:

  1. Go to the Vonage Prefix Mapping object tab, click Vonage Prefix Mappings View in the View list and click Go!. Any existing mappings appear.
  2. Click New Vonage Prefix Mapping. A new Callback Prefix Mapping record appears.
  3. Provide the following information. Ignore other fields.

    FieldDescriptionExample
    DescriptionA name for this mapping.Callback for UK numbers
    Dialled Number PrefixA dialed number prefix that VCC will use to locate this mapping record.+44
    Presented Callback Number

    The callback number that VCC will display when the dialed number's prefix matches the value in the Dialled Number Prefix field.

    You can only use callback numbers that are configured for your account. If you use a number that is not configured for your account, VCC cannot make outbound calls that use this prefix mapping record. The error message "The call to number dialed number could not be made as the presented CLID presented callback number is restricted or is not available on your account." appears in your agent's ContactPad.

    02072068888
  4. Click Save.
    Using the example values in step 3, when an agent clicks to dial a phone number with the prefix +44, VCC uses 0207206888 as the callback number. In the absence of any other mappings, when an agent clicks to dial a phone number with any other prefix, VCC uses the default callback number. This default callback number can be for the account or for the agent. Which callback number VCC uses depends on the current configuration. For more information about callback numbers, see Callback numbers.


Your prefix can contain as many digits as you want. You can specify the country code, area code, or even the entire telephone number. If the dialed number matches more than one mapping, Vonage Contact Center (VCC) uses the most specific mapping. For example, you create mappings for the prefixes +44, +4420 and +44 20 7946 0900. When your agent clicks to dial +44 20 7946 0900, VCC uses the mapping record for +44 20 7946 0900.

VCC will only find your prefix mapping records if you use exactly the same format as the dialed telephone number. For example, if you create a prefix mapping record with the prefix in national format (such as 020) but the dialed number is in E.164 format (such as +4420), VCC cannot find your mapping record. If you cannot be sure which format the dialed numbers use, create mappings for multiple formats: 020, +4420, 004420, and so on.

Special characters in dialed numbers are ignored. For example, VCC will locate a prefix mapping of +44 or +4470 when an agent clicks to dial +(44) 7-000.000.000.

 Example

Your company sells in both the United Kingdom and France. You want to present a different callback number when your sales agents make outbound calls to either of those countries. (Your sales agents must belong to the Sales profile.) The rest of the users will use the default callback. Your callback number for the UK is 01234567890 and your callback number for France is 123456789.

To configure this example, you must perform the following tasks:

  • Create a custom settings record for the Sales profile and set the value of the Callback Number Selector Class field to VCCCore.SelectPresentedCLIDByNumberPrefix.

    Leave the Callback Number Selector Class field value empty in the default custom settings for the organization level.
  • Create one Vonage Prefix Mapping record, with the following values:
    • Dialled Number Prefix: +33

    • Presented Callback Number: 123456789

    • Description: Callback for French numbers

  • Create another Vonage Prefix Mapping record with these values:
    • Dialled Number Prefix: +44

    • Presented Callback Number: 01234567890

    • Description: Callback for UK numbers

Now, whenever your sales agents make an outbound call to a French number, VCC presents the French callback number. Similarly, when a sales agent makes an outbound call to a UK number, VCC presents the callback number for the UK. When any other agent makes a click to dial call, VCC presents the default callback number because you have not configured the agents to use this feature.

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