Prefix Information

The prefix 840 is part of area code 312 serving Chicago, Illinois.

This exchange contains 10,000 possible phone numbers (312-840-0000 through 312-840-9999).

Browse Numbers in This Prefix

312-840-0000-0999 312-840-1000-1999 312-840-2000-2999 312-840-3000-3999 312-840-4000-4999 312-840-5000-5999 312-840-6000-6999 312-840-7000-7999 312-840-8000-8999 312-840-9000-9999

Sample Numbers

(312) 840-0000 (312) 840-1234 (312) 840-2000 (312) 840-3333 (312) 840-4444 (312) 840-5555 (312) 840-6000 (312) 840-7777 (312) 840-8888 (312) 840-9999