NPA 866

Opened 2000. The third-most-saturated prefix.

90.54%
in use as of 2026-07-25
7,224,859
numbers in use
755,141
spare
7,980,000
total pool size
175,228
in transit (mid-port)
78,493
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.

2.0M4.0M6.0MWorkingAssignedReservedDisconnectTransitUnavailSuspend2017-10-282023-09-232026-07-25NPA 866 total in use: 7.2M
  • Working7.0M
  • Assigned0
  • Reserved6K
  • Disconnect78K
  • Transit175K
  • 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%2017-10-282023-09-092026-07-25

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) 1,296,199 18.6%
Bandwidth (JY) 793,947 11.4%
Twilio (TW) 786,258 11.3%
Mayfair Communication (MY) 371,466 5.3%
AT&T (AT) 366,421 5.3%
Signal One (SO) 257,868 3.7%
Inteliquent (JF) 195,613 2.8%
Lumen Technologies (KS) 173,795 2.5%
Invoca (YV) 173,545 2.5%
Toll Free Management (MT) 170,759 2.5%

Compare other NPAs

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