You can delete an entry from the Phone Book Special Numbers form. An entry cannot be deleted if the entry exists on one or more products, or if it exists in one or more phone books. The entry must be removed from all products and phone books before it can be deleted. The basic steps are:
Remove the entry from all products in the Product Catalog.
Via Customer Management (or SDK), synchronize the service(s) to remove the entry from the respective phone books.
Remove the entry from the Phone Book Special Numbers form in Product Management
Removing Special Numbers from Products
Use the Add/Edit Product forms in the Product Catalog to remove the number from all products with which it is associated. See Adding/Removing Entries on a Product.
Synchronizing Services
Use the Phone Book Refresh function (Actions > Refresh) in Customer Management to remove entries on a service-by-service basis, or synchronize services in bulk via SDK. Synchronization removes an entry from a phone book if the service does not have the corresponding product assigned.
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See Synchronizing the Phone Book to Products Active on the Service for details.
Removing the Special Number from the Phone Book Special Numbers Window
To do this:
Select the entry in the Phone Book Special Numbers window.

Right-click and choose Delete.