309-475 phone numbers

Numbers 309-475-0000 to 309-475-9999 are assigned to Frontier North, Inc. in Saybrook, IL. 3 of its ten thousand-number blocks are assigned to other carriers (number pooling).

Not assigned to any carrier: 309-475-0xxx, 309-475-3xxx, 309-475-4xxx, 309-475-5xxx — calls from these use spoofed caller IDs.

Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.

Reported numbers in 309-475