Prefix Information

The prefix 231 is part of area code 312 serving Chicago, Illinois.

This exchange contains 10,000 possible phone numbers (312-231-0000 through 312-231-9999).

Browse Numbers in This Prefix

312-231-0000-0999 312-231-1000-1999 312-231-2000-2999 312-231-3000-3999 312-231-4000-4999 312-231-5000-5999 312-231-6000-6999 312-231-7000-7999 312-231-8000-8999 312-231-9000-9999

Sample Numbers

(312) 231-0000 (312) 231-1234 (312) 231-2000 (312) 231-3333 (312) 231-4444 (312) 231-5555 (312) 231-6000 (312) 231-7777 (312) 231-8888 (312) 231-9999