Glossary · POTS

What is POTS?

POTS — plain old telephone service — is the traditional analog telephone service delivered over copper wire pairs, essentially unchanged in concept since the early 20th century. A POTS line carries voice as an analog electrical signal between your premises and the carrier’s central office, with the line itself powered by the phone network.

POTS is the consumer/end-user face of the PSTN (the global switched telephone network). For a century it defined what “a phone line” meant; today carriers are actively retiring it.

How a POTS line works

A dedicated copper pair runs from the building to the carrier. The line carries about 48 volts DC from the central office — which is why old phones worked during power outages — and voice rides the wire as an analog waveform in the 300–3400 Hz band. One line, one conversation, one number.

That narrow band is also the ceiling: no HD audio, no data beyond dial-up speeds, no second simultaneous call without a second physical pair.

Why POTS lines are going away

Carriers are phasing out copper: the equipment is aging, the technicians who maintain it are retiring, and regulators (in the US, FCC orders since 2019) have cleared the path for carriers to stop selling and supporting POTS. The practical consequences businesses see now:

Steep price increases — legacy POTS lines commonly bill several hundred dollars a month as carriers push migration.
No new installs in many areas, and long repair times where copper remains.
Forced migration notices as exchanges are decommissioned.

What still runs on POTS — and what replaces it

The stubborn holdouts are the non-phone devices wired to copper: fire alarm panels, elevator phones, fax machines, gate entry systems, and some point-of-sale terminals. Replacement paths:

Business voice → VoIP/cloud phone systems — better audio, lower cost, every modern feature.
Fax → online fax or T.38 over IP.
Analog devices (alarm panels, elevators) → an ATA (analog telephone adapter) or a cellular/LTE POTS-replacement gateway that presents a dial tone to the device while connecting over modern networks. Life-safety lines must meet code requirements (battery backup, supervised connections) — involve your alarm/elevator vendor.

Common questions

Is POTS the same as a landline?

Colloquially yes — a classic landline is a POTS line. Technically “landline” sometimes also covers digital wired services like ISDN or fiber voice. When a carrier or vendor says POTS, they mean specifically the analog copper service.

Why is my POTS line so expensive now?

Carriers price legacy copper to push migration: maintenance costs on a shrinking network are high, and regulatory changes let carriers raise rates or exit the service. Month-over-month increases on grandfathered business POTS lines are the most common trigger for finally migrating.

Do POTS lines work during power outages?

Traditional POTS is line-powered from the central office, so a basic corded phone keeps working in a local outage — historically POTS’s biggest advantage. The modern picture is weaker: cordless phones still need wall power, and as carriers move copper onto fiber/IP backhaul, that guarantee erodes. VoIP achieves equivalent resilience with UPS backup and mobile failover.

What should a business replace POTS lines with?

Voice lines: a cloud business phone system — DialPhone runs voice, SMS, fax, and video from $24/user/month with a 99.999% uptime SLA. Device lines (alarms, elevators, gates): an ATA or LTE POTS-replacement gateway sized to code requirements for that device class. Most businesses run both: cloud for people, gateways for the handful of analog devices.

See DialPhone migration

AI business phone system → · VoIP vs landline → · Pricing →

PSTN — the network POTS lines connect to
ATA — keep analog devices alive on modern networks
ISDN — POTS’s digital sibling, also retiring
VoIP vs landline — the full migration comparison
E911 — emergency calling requirements after migration