Block List: Edit Range
This screen allows you to add a phone number range to the block list, or to edit a phone number range already in the block list.
The count of phone numbers you can block overall is limited. A good rule of thumb is to define a range of 10,000 phone numbers, which would encompass all the numbers in the same area code and exchange.
Each phone number entry box will automatically recognize the locality of the phone number you type in, and will format it accordingly.