I am subscribed to Usage Controls. Once you subscribe to Usage Controls and are on your Usage Controls dashboard, click on "Add Blocks". Check the box next to "Name", and enter a name that designates the caller that you want to block (for example, "International Caller 1"). In the box below next to "Contact Info", enter the international number. According to the website, international numbers will need to include the international dialing prefix, country code, city code (area code) and local number. (Eg. 011-52-443-123-4567 or 00-46-340-1234-5678). Finally, select "Domestic or International Number" from the drop-down box, and click the "Add" button.