The NPAC (Number Portability Administration Center) is the authoritative national database of ported and pooled phone numbers in the US. When a number moves from one carrier to another, the NPAC record is what actually changes: it maps the ported number to the LRN of the switch that now serves it and broadcasts that mapping to every participating carrier. Until the NPAC record activates, no port has really happened — everything before that moment is paperwork.
Operators tend to treat the NPAC as invisible plumbing, and most days it is. But every porting question that lands on a support desk — why the port has not cut over, why calls still hit the old carrier, why a rate changed after a port — resolves to what the NPAC record says and when it changed. Number porting is daily work for SIPNEX, an FCC-licensed carrier — what follows is the working explanation rather than the acronym-expansion one.
Where the NPAC sits in the port flow
A port involves three instruments before the database ever changes. Your new carrier collects your authorization on an LOA, turns it into an LSR — the carrier-to-carrier order form submitted to your losing carrier, and the losing carrier answers with a FOC, the committed release date. All of that is negotiation between two carriers. The NPAC is where the result gets executed.
On or around the FOC date, the gaining carrier activates the port in the NPAC. That activation writes the new routing record and pushes it out to the industry — and that push, not the FOC itself, is the actual cutover. One moment calls route to the losing carrier; the next, the network-wide routing data says the number lives somewhere else. This is why a correctly run port has zero downtime, a point our number porting guide covers step by step: the switch happens at the database level, not with a physical disconnect.
The activation itself takes effect quickly. The 7–14 business days of a standard simple port is not the NPAC being slow — it is the carrier-to-carrier work in front of it: gathering account data that matches the losing carrier’s records, LSR validation, rejection-and-resubmit cycles, and FOC scheduling.
From Neustar to iconectiv: who runs it
The NPAC is not owned by any carrier. It is operated by a neutral administrator — the role is formally called the LNPA (Local Number Portability Administrator) — selected through an FCC-managed procurement. Neustar held the contract for roughly 18 years; iconectiv, an Ericsson subsidiary, won the LNPA contract in 2015 and took over from Neustar in 2018, completing the transition region by region.
That regional structure matters more than the vendor name: the NPAC is organized as a set of US regional databases rather than one monolith, though for practical purposes carriers interact with it as a single system. The scale is real — iconectiv reports the system holds around a billion telephone number records and processes hundreds of thousands of porting transactions a day.
For an operator, the takeaway is neutrality. Your losing carrier does not control the database that routes your numbers. They can reject a defective LSR with a reason code, but they cannot reach into the NPAC and hold a validly ported number.
SOA in, LSMS out: how a record propagates
The NPAC has a clean input side and output side, and knowing both explains most “the port completed but calls are still going to the old carrier” tickets.
Input: SOA. Carriers submit port and subscription data into the NPAC through their SOA (Service Order Administration) system — or, for smaller operators, a web-based Low Tech Interface. This is how the gaining carrier creates and then activates the port record.
Output: LSMS broadcast. When a port activates, the NPAC broadcasts the change to every participating carrier’s LSMS (Local Service Management System) — the local copy of portability routing data each network queries when it routes calls. The NPAC is the master; the LSMSs are the distributed working copies.
What the record says. The core mapping is ported telephone number → LRN of the new serving switch. Numbers that have never been ported have no NPAC entry at all and simply route on their native prefix. What carriers do with that mapping at call time — the dip, the rn parameter, and why termination billing follows the routing number — is its own subject, covered in our LRN explainer. The short version: the NPAC is where the answer to a dip comes from; the dip is how the network asks the question.
So when a port has activated but some calls still misroute, the usual suspect is propagation — a carrier whose local routing data has not caught up — not the port itself. It is also why post-port verification, inbound and outbound, belongs on every cutover checklist.
What the NPAC does not cover
The NPAC’s scope is narrower than “all US numbers,” and the gaps are where porting expectations go wrong:
- Toll-free numbers. 8XX numbers are not in the NPAC. They move between providers through a RespOrg change in the toll-free registry — a different process with its own timeline, explained in our RespOrg glossary post.
- Never-ported numbers. No entry exists until a number ports for the first time. Absence from the NPAC is normal, not an error.
- The customer-facing order. The NPAC executes routing changes; it does not validate your LOA, chase your losing carrier, or fix a name mismatch. Those failures happen upstream, in the LSR and FOC exchange, which is where nearly all port delays live.
Frequently asked questions
What does NPAC stand for?
NPAC stands for Number Portability Administration Center. It is the authoritative national database of ported and pooled telephone numbers in the US. When a number is ported, the NPAC records which carrier’s switch now serves it (via its LRN) and broadcasts that routing data to every participating carrier, so calls to the number reach the new network.
Who runs the NPAC?
A neutral administrator called the LNPA (Local Number Portability Administrator), selected through FCC-managed procurement. Neustar operated the NPAC for roughly 18 years; iconectiv, an Ericsson subsidiary, won the contract in 2015 and completed the takeover in 2018. No carrier owns or controls the database, which is what keeps porting neutral — your losing carrier cannot block a valid port at the database level.
Is every phone number in the NPAC?
No. Only numbers that have been ported (or pooled) have NPAC records. A number that has never left its original carrier routes on its native prefix and has no entry at all. Toll-free numbers are never in the NPAC — they change providers through a RespOrg transfer in the toll-free registry instead of the LNP process.
When does the NPAC actually move my number?
The moment the gaining carrier activates the port record. Activation writes the new number-to-LRN mapping into the NPAC and broadcasts it to every participating carrier’s LSMS — the local routing copy each network queries. That broadcast is fast; if some calls still misroute afterward, the usual cause is a carrier whose local copy has not refreshed yet, not the port itself. What date activation is scheduled for, and who to chase if it slips, are FOC-side questions covered in our FOC date explainer.
Port fees are one thing the NPAC never charges you for — and neither does SIPNEX. We are an FCC-licensed carrier with no port-in or port-out fees on US numbers, a 7–14 business day standard for simple ports, and A-level STIR/SHAKEN attestation on your ported numbers from the first call. Open a port order or check our wholesale rates first.
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