{"area_code":"815","type":"geographic","status":"active","country":"US","region":"Illinois","region_code":"IL","principal_city":"Rockford","cities":["Rockford","Joliet","DeKalb","Crystal Lake","Romeoville","Belvidere","Freeport","Kankakee","Loves Park","Machesney Park","McHenry","Woodstock"],"timezone":"America/Chicago","timezone_label":"Central Time","current_local_time":"2026-08-04 15:02:00","ten_digit_dialing":true,"service_type":null,"overlay_codes":["779"],"nearby_codes":["779","312","773","872","331","630"],"summary":"Area code 815 covers Rockford and nearby cities including Joliet, DeKalb, Crystal Lake in Illinois, in the Central Time.","carrier_summary":{"nxx_prefixes":786,"blocks":5553,"wireless_pct":30,"top_carriers":[{"name":"ONVOY, LLC","blocks":589},{"name":"FRONTIER NORTH, INC. - IL","blocks":568},{"name":"T-MOBILE USA, INC.","blocks":552},{"name":"ILLINOIS BELL TEL CO","blocks":540},{"name":"LEVEL 3 COMMUNICATIONS, LLC - IL","blocks":402},{"name":"CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL","blocks":314}],"per_number":"https://areacode.fyi/api/v1/carrier/{number}"},"canonical_url":"https://areacode.fyi/815","source":"North American Numbering Plan Administrator via areacode.fyi","data_date":"2026-08-02"}