NPA 866

Opened 2000. The third-most-saturated prefix.

91.24%
in use as of 2026-06-13
7,280,598
numbers in use
699,402
spare
7,980,000
total pool size
103,317
in transit (mid-port)
75,921
in disconnect aging

About NPA 866

866 came online in 2000 and has been a workhorse for two decades. About 92% of its inventory is in use, with the remaining spare pool serving as a modest buffer.

Status decomposition over time

Every toll free number sits in exactly one status: working (in active use), assigned (allocated but not yet routing), reserved (held briefly during pickup), disconnect (aging out before returning to spare), transit (mid-port between RespOrgs), unavailable (held by Somos), or suspend. Watch the mix shift as the prefix has matured.

2.0M4.0M6.0MWorkingAssignedReservedDisconnectTransitUnavailSuspend2017-10-282023-08-262026-06-13NPA 866 total in use: 7.3M
  • Working7.1M
  • Assigned0
  • Reserved1K
  • Disconnect76K
  • Transit103K
  • Unavail2K
  • Suspend0

Fill % over time

Percentage of NPA 866's 7,980,000 (or 7,870,094 for 800) total possible numbers that are currently in use. 100% means every assignable number has been claimed.

0%25%50%75%100%2017-10-282023-08-122026-06-13

Top RespOrgs holding NPA 866

Ten RespOrgs sit on most of NPA 866's working inventory. Click any name for their full profile: trajectory, opportunism index, vanity holdings, and how their NPA mix compares to the industry total above.

RespOrg Numbers in NPA 866 Share of working inventory
Verizon Business (VZ) 1,298,475 18.3%
Bandwidth (JY) 794,104 11.2%
Twilio (TW) 770,241 10.9%
AT&T (AT) 382,254 5.4%
Mayfair Communication (MY) 370,034 5.2%
Signal One (SO) 260,713 3.7%
Inteliquent (JF) 195,696 2.8%
Invoca (YV) 173,634 2.4%
Lumen Technologies (KS) 173,426 2.4%
Toll Free Management (MT) 168,611 2.4%

Compare other NPAs

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