NPA 866

Opened 2000. The third-most-saturated prefix.

92.49%
in use as of 2026-04-25
7,380,314
numbers in use
599,686
spare
7,980,000
total pool size
216,143
in transit (mid-port)
65,728
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.

2.0M4.0M6.0MWorkingAssignedReservedDisconnectTransitUnavailSuspend2017-10-282023-07-152026-04-25NPA 866 total in use: 7.4M
  • Working7.1M
  • Assigned8
  • Reserved1K
  • Disconnect66K
  • Transit216K
  • 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%2017-10-282023-07-152026-04-25

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) 1,299,512 18.3%
Bandwidth (JY) 788,582 11.1%
Twilio (TW) 764,474 10.8%
AT&T (AT) 393,643 5.5%
Mayfair Communication (MY) 367,987 5.2%
Signal One (SO) 261,960 3.7%
Inteliquent (JF) 195,736 2.8%
Lumen Technologies (KS) 174,187 2.5%
Invoca (YV) 173,637 2.4%
Toll Free Management (MT) 173,032 2.4%

Compare other NPAs

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