Illinois, United States
Central Time
12:00 AM
Area Code
861
State / Province
Illinois
Country
United States
Time Zone
Central Time
City data unavailable for this area code.
Use the E.164 format for clickable phone links (RFC 3966):
<a href="tel:+18615550100">+18615550100</a><a href="tel:+18615550199">+18615550199</a>Look up which exchange in Illinois a specific 861 number is homed to, and whether its block is wireline or wireless. See what a reverse lookup can establish before relying on the answer.
Area code 861 is a North American Numbering Plan (NANP) telephone area code assigned to Illinois, United States. It is one of 17 area codes serving Illinois. As population and demand for phone numbers grew, the region was divided into multiple numbering plan areas to avoid exhausting the available 7-digit number pool.
Yes. 861 is an active North American Numbering Plan (NANP) area code, currently assigned to Illinois, United States. It is safe to answer or dial calls using this area code.
All numbers in the 861 area code observe Central Time (IANA timezone: America/Chicago). Central Time is UTC−6 in winter (CST) and UTC−5 in summer (CDT). When placing a call to a 861 number from a different time zone, check the current local time above to avoid calling outside of business hours.
From within Illinois, dial the 7-digit local number directly if calling within the same rate center, or dial 1 + 861 + 7-digit number for long-distance calls within North America. From outside the US or Canada, dial your country's international exit code followed by 1 861 XXX XXXX. The country code for both the United States and Canada in NANP is +1.
Format 861 numbers using E.164 notation as required by RFC 3966: prefix with +1 and omit dashes and parentheses (e.g., +18615550100). This format ensures tel: links work correctly on all mobile browsers and VoIP apps. See the tel: URI formatting guide for complete examples.