Definition

POTS line

Also known as: analog line, copper line, analog telephone circuit, landline

A POTS line is a single analog telephone circuit delivered over a copper pair, identified by its own telephone number and billed individually.

How it works

Each line is a dedicated pair from the carrier's wire center to the premises, terminating at a demarcation point. One line carries one conversation or one data session at a time. Businesses often have many — one per alarm panel, one per elevator, one per fax machine, one per credit-card terminal.

Why it matters

POTS lines are billed per line and their rates have risen sharply as carriers withdraw from copper. Because they were installed one at a time over decades, most organizations do not know how many they have or what is connected to each one — which is why a line inventory is the first step in any migration.

Common use cases

A dedicated line for a fire alarm communicator
An elevator emergency phone line
A fax or point-of-sale line in a retail location

Counting lines is deceptively hard. Invoices describe billing accounts rather than physical circuits, and the equipment on a line rarely appears anywhere in the record.

Building an inventory that is actually complete

Because the record is unreliable, a usable inventory comes from reconciling three independent sources rather than trusting any one.

Carrier invoices and circuit inventories establish what is being billed. Request a full circuit list per account rather than working from the summary invoice, and expect it to describe billing arrangements rather than physical circuits.

A physical walk of each site establishes what exists. Trace each pair from the demarcation point and label both ends as you go. This is the step that finds equipment nobody documented, and it is the step most often skipped.

Departmental knowledge establishes purpose. Facilities, security, IT and finance each know about circuits the others do not, and the alarm and elevator service files frequently name lines that appear nowhere in telecom records.

Record, for each line: the number, the serving wire center, the physical termination, what is connected, who depends on it, and what it would break. Lines with an unknown far end are open items — not disconnect candidates.

Common misconceptions

“If we do not use desk phones any more, we do not have POTS lines.”

Most surviving POTS lines serve machines, not people — alarm panels, elevator phones, fax machines, gate controllers. They are easy to overlook precisely because nobody makes calls on them.

Frequently asked questions

How much does a POTS line cost?

Rates vary widely by carrier and location and have been increasing as copper is withdrawn. Individual lines exceeding several hundred dollars per month are common, and the U.S. Bureau of Labor Statistics tracks landline price increases well above general inflation.

How do I find all our POTS lines?

Start with carrier invoices and circuit inventories, then walk each site to trace what is physically connected. Billing records alone routinely miss lines, and physical inspection routinely finds equipment nobody documented.