866 area code — toll-free toll-free

Data: NANPA public reports, current as of July 28, 2026.

The 866 area code covers NANP AREA, Eastern time zone, and dates back to July 29, 2000. The same territory is also served by its overlay codes (800/833/844/855/866/877/888 complex). Keep in mind the code identifies where the number was registered; the person calling may be elsewhere.

The code was carved out of 800 (2000).

To check where a specific 866 number was issued, look up its six-digit prefix; to check who is actually calling, ignore the display and verify through an official callback number — caller ID is assertable and routinely spoofed.

As an Easily Recognizable Code (matching last digits), 866 is reserved for toll-free service: the called business pays for the call, and the number works across the US, Canada and much of the Caribbean. Toll-free numbers are assigned individually from the SMS/800 registry run by Somos, not in carrier prefix blocks — which is why no rate-center table exists for this code. See the toll-free profile of 866 for how these numbers behave in practice.

FAQ

Is 866 a toll-free number?

Yes — 866 is one of the seven US toll-free codes (800, 833, 844, 855, 866, 877, 888): the called business pays for the call.

Why do 800 and 866 cover the same place?

They are overlays: when a code runs low on numbers, a new code is added over the same territory instead of splitting it. The 800/833/844/855/866/877/888 complex shares one service area, and local calls are dialed with 10 digits.

Why am I getting spam calls from 866 numbers?

Scammers spoof real area codes so calls look legitimate. A displayed 866 number does not prove the call originated there — see our guide to spotting spoofed calls.