Prefix Information

The prefix 991 is part of area code 331 serving Aurora, Illinois.

This exchange contains 10,000 possible phone numbers (331-991-0000 through 331-991-9999).

Browse Numbers in This Prefix

331-991-0000-0999 331-991-1000-1999 331-991-2000-2999 331-991-3000-3999 331-991-4000-4999 331-991-5000-5999 331-991-6000-6999 331-991-7000-7999 331-991-8000-8999 331-991-9000-9999

Sample Numbers

(331) 991-0000 (331) 991-1234 (331) 991-2000 (331) 991-3333 (331) 991-4444 (331) 991-5555 (331) 991-6000 (331) 991-7777 (331) 991-8888 (331) 991-9999