{"area_code":"231","type":"geographic","status":"active","country":"US","region":"Michigan","region_code":"MI","principal_city":"Muskegon","cities":["Muskegon","Norton Shores","Shelby"],"timezone":"America/New_York","timezone_label":"Eastern Time","current_local_time":"2026-08-04 16:01:01","ten_digit_dialing":false,"service_type":null,"overlay_codes":[],"nearby_codes":["616","269","989","517","810","248"],"summary":"Area code 231 covers Muskegon and nearby cities including Norton Shores, Shelby in Michigan, in the Eastern Time.","carrier_summary":{"nxx_prefixes":572,"blocks":3770,"wireless_pct":30,"top_carriers":[{"name":"ONVOY, LLCV - MI","blocks":744},{"name":"NEW CINGULAR WIRELESS PCS, LLC - IL","blocks":378},{"name":"MICHIGAN BELL TEL CO","blocks":305},{"name":"CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI","blocks":284},{"name":"OMNIPOINT COMMUNICATIONS MIDWEST OPERATIONS, LLC","blocks":283},{"name":"FRONTIER NORTH, INC. - MI","blocks":236}],"per_number":"https://areacode.fyi/api/v1/carrier/{number}"},"canonical_url":"https://areacode.fyi/231","source":"North American Numbering Plan Administrator via areacode.fyi","data_date":"2026-08-02"}