Exchange · Chicago, IL
(312) 604-xxxx
Every number from 312-604-0000 to 312-604-9999. NANPA records the exchange as assigned to Verizon Business for Chicago, IL. Robocall and scam operations often use many numbers from one exchange, so if one number here is a shady call, its neighbors deserve a second look.
Reported numbers starting 312-604
About the 312-604 exchange
312-604 is an exchange (the first six digits of a phone number) in area code 312, which covers Illinois. NANPA, which runs the North American Numbering Plan, assigned it to Verizon Business for the Chicago, IL rate center. Numbers from this carrier are usually VoIP / internet phone lines.
People keep their number when they move or switch carrier, so this is where the number was first assigned, not where the caller is today. Local time for 312-604 numbers is usually Central time. Scammers can also fake (spoof) any number, so a call that shows a 312-604 number may not come from Verizon Business at all.