← Area code 708
708-721 phone numbers
Numbers 708-721-0000 to 708-721-9999 are assigned to Verizon Wireless in Northbrook, IL.
Not assigned to any carrier: 708-721-3xxx, 708-721-4xxx, 708-721-5xxx, 708-721-6xxx, 708-721-8xxx, 708-721-9xxx — calls from these use spoofed caller IDs.
Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.