Estimated reading time: 9 minutes
If you manage communications, IT, or facilities for a business, you’ve probably heard the term “POTS lines” come up more frequently over the past few years and not in a good way.
POTS lines have been the backbone of business telephone systems for over a century. Fire alarms, elevator phones, fax machines, point-of-sale terminals, security systems: the list of things that depend on them is longer than most people realize. But traditional carriers are actively shutting them down, and the window to plan a managed transition is closing fast.
This guide explains exactly what POTS lines are, why they’re being retired, and what businesses should do before their critical systems stop working.
If you are a facilities manager, operations director, or compliance officer, this is your problem more than it is your IT department’s. The decisions here center on uptime, regulatory exposure, and liability. The urgency is not manufactured. It arrives in the form of a carrier retirement notice, a building inspection finding, or an insurance audit that flags a non-functional fire alarm communication path.
What Are POTS Lines?
POTS stands for Plain Old Telephone Service. It refers to the traditional analog telephone system delivered over a network of copper wires that has been in place since the late 1800s.
When you pick up a traditional landline phone and hear a dial tone, that’s POTS. The signal travels as an analog electrical current over a dedicated copper circuit from your premises to a telephone exchange. No internet required, no software, no configuration.
POTS lines are part of what’s known as the Public Switched Telephone Network (PSTN), the global system of interconnected copper-wire telephone networks that telecommunications companies built and maintained over the last century.
Key characteristics of POTS lines
- Analog signal: voice is transmitted as a continuous electrical waveform, not digital data
- Dedicated copper circuit: a physical wire runs from the building to the telephone exchange
- Loop-powered: the line draws power from the telephone exchange, meaning it works even during a power outage
- Single-purpose: each line carries one call at a time
What Do Businesses Use POTS Lines For?
This is where most facilities and compliance teams are surprised. POTS lines aren’t just desk phones. In a typical commercial building, POTS lines are quietly running a wide range of systems:
- Fire alarm panels: most local fire codes require a dedicated phone line for alarm monitoring and reporting to emergency services (see NFPA 72 2025 requirements and the NFPA 72 standard)
- Elevator emergency phones: building codes in most states mandate a phone in every elevator cab
- Fax machines: still common in healthcare, legal, and financial sectors
- Security and access control systems: gate dialers, door buzzers, alarm panels
- Point-of-sale terminals: older payment processing equipment that uses a phone line as a backup
- Building management systems: HVAC controls, environmental monitoring, and emergency notification systems
- DSL internet connections: some businesses in areas with limited connectivity still rely on DSL, which runs over copper
In a multi-site enterprise (a grocery chain, a hospital network, a bank with branch locations), there can be hundreds or thousands of POTS lines spread across locations, many of which nobody has documented in years.
Why Are POTS Lines Being Retired?
Maintaining aging copper infrastructure is expensive. AT&T, Verizon, and other major carriers have been pushing regulators for years to allow them to retire their copper networks, and the FCC has largely allowed it.
In 2019, the FCC issued rules that allow carriers to discontinue copper-based services, including POTS lines, with as little as 180 days notice to customers. Since then, carriers have been systematically decommissioning copper infrastructure across the country.
The result: POTS lines are becoming unavailable in many areas, and in others they still exist but at sharply increased prices as carriers cost-recover on shrinking infrastructure. Businesses that were paying $30–$50 per line per month are now seeing bills of $150–$300 or more for the same service.
What Happens When a POTS Line Is Discontinued?
When a carrier retires service to your area, they notify you that your line will be disconnected. If you haven’t migrated to an alternative by that date, the line simply stops working.
For a desk phone, that’s an inconvenience. For a fire alarm panel or an elevator phone, it can mean:
- Failed safety inspections: many local codes require a working phone connection for fire alarm and elevator systems to pass inspection
- Fines and citations: a non-functional emergency communication system can trigger regulatory penalties
- Liability exposure: if an emergency occurs and the alarm system couldn’t reach emergency services because the phone line was dead, the consequences can be severe
- Business disruption: payment terminals and security systems that lose their backup phone connection may fail in ways that aren’t immediately obvious
This is why the POTS retirement is treated as a critical infrastructure issue, not a technology procurement decision. It is a compliance and risk management program.
What Are Businesses Replacing POTS Lines With?
There are several modern alternatives to POTS lines, and the right choice depends on what the line is being used for:
Managed POTS replacement solutions
Purpose-built services from providers like MarketSpark replace the physical copper line with a cellular or IP-based connection that behaves identically to a POTS line from the perspective of the connected device. The fire alarm panel, elevator phone, or fax machine doesn’t know anything has changed. It still gets a dial tone and connects as expected.
This is the preferred approach for life-safety systems (fire alarms, elevators) where the connected device cannot be changed without costly recertification, and where regulatory compliance depends on the line behaving in a specific way.
VoIP (Voice over IP)
Voice over IP replaces analog calling with digital calls sent over an internet connection. It’s suitable for desk phones and general office telephony, but is often not appropriate for fire alarm panels and similar life-safety devices, which require specific analog signaling that VoIP doesn’t always support reliably. Read more in our guide to analog vs. digital voice communications.
Analog Telephone Adapters (ATAs)
An ATA converts a VoIP connection into an analog signal, allowing legacy devices to connect over IP infrastructure. Results vary depending on the device and the quality of the internet connection.
Cellular backup systems
Some businesses install cellular-based communication modules directly in panels and systems that previously relied on POTS lines, eliminating the need for a phone line entirely. This requires device-level changes and is a longer-term infrastructure upgrade.
How Should Businesses Approach POTS Line Replacement?
The biggest mistake businesses make is treating POTS replacement as a line-by-line swap. In a multi-site organization with hundreds of lines across dozens of locations, that approach creates years of project risk, inconsistent outcomes, and significant ongoing management overhead.
A better approach:
- Audit every POTS line across all locations: know exactly what you have, what it’s connected to, and what the replacement requirement is for each device type
- Prioritize life-safety lines first: fire alarms, elevators, and emergency communication systems have the most regulatory and liability exposure
- Work with a managed POTS replacement provider: a provider that handles project management, nationwide installation, and ongoing monitoring takes the burden off internal facilities and compliance teams and ensures consistent compliance across all sites
- Don’t wait for a disconnection notice, a building inspection finding, or an insurance audit: by the time you receive one, lead times for equipment and installation may mean you’re already behind
The Bottom Line
POTS lines have served businesses reliably for over a hundred years. But the infrastructure that supports them is being actively retired, costs are rising sharply, and the timeline for replacement is no longer theoretical. It’s measured in months, not years, for many businesses.
Understanding what your POTS lines are connected to, what the regulatory requirements are, and what a compliant replacement looks like is the first step to getting ahead of it.
MarketSpark specializes in fully managed POTS replacement for enterprise and multi-site businesses, handling everything from the initial audit through nationwide installation and ongoing monitoring. If you have received a carrier retirement notice, are preparing for a building inspection, or want to get ahead of the shutdown before it becomes urgent, contact MarketSpark or learn more about our POTS replacement solution.
Frequently Asked Questions
A POTS line (Plain Old Telephone Service) is a traditional analog telephone connection delivered over a physical copper wire. It has been the standard for voice communication since the late 1800s and is still widely used today to connect fire alarm panels, elevator phones, fax machines, security systems, and other devices that require a dedicated phone connection.
Major carriers like AT&T and Verizon are retiring their copper wire infrastructure because it is expensive to maintain and has been largely superseded by IP-based and cellular networks. The FCC has allowed carriers to discontinue copper-based services with as little as 180 days notice, and the 2024 Copper Retirement Order has accelerated the timeline further. In many parts of the country, POTS lines are already unavailable or priced so high they are no longer practical.
If a fire alarm panel is connected to a POTS line that gets disconnected, the alarm loses its ability to report to the monitoring center and emergency services. This can result in failed safety inspections, fines, and significant liability exposure. Fire alarm panels connected to POTS lines need to be migrated to a compliant replacement, typically a managed POTS replacement solution that provides an equivalent analog signal over cellular or IP infrastructure, before the line is discontinued.
For life-safety systems like fire alarms and elevator phones, a managed POTS replacement solution is generally the best option. These services replace the physical copper line with a cellular or IP-based connection that behaves identically to a POTS line, meaning the connected device requires no modification. For general office telephony, VoIP is a common and cost-effective alternative. The right choice depends on what the line is connected to and what regulatory requirements apply.
POTS line pricing has increased sharply as carriers reduce their copper infrastructure. Businesses that were previously paying $30–$50 per line per month are now commonly seeing rates of $150–$300 or more for the same service, with some carriers pricing even higher in areas where copper maintenance costs are especially high. Many businesses find that migrating to a managed replacement solution is significantly more cost-effective than staying on legacy POTS.
The most reliable approach is a formal POTS line audit across all your locations. Many businesses, particularly those with multiple sites, have POTS lines connected to systems that were installed years ago and are no longer actively tracked. A thorough audit identifies every line, what it is connected to, and what the replacement requirement is for each device type. MarketSpark provides nationwide POTS line auditing as part of its managed replacement service.
Typically Facilities, Operations, or EHS/Compliance, not IT. POTS replacement decisions center on uptime, regulatory compliance, and liability exposure, not technology selection. The CIO may not be the primary stakeholder at all. The people most accountable are those responsible for building compliance, safety systems, and operational continuity. This is why the conversation usually starts with a facilities manager or operations director, not a technology procurement team.
Traditional POTS lines draw power directly from the telephone exchange rather than from the building’s electrical supply, which means they typically continue to work during a local power outage. This is one reason they have historically been required for fire alarms and emergency communication systems. Modern replacement solutions address this by including battery backup to maintain connectivity during outages, ensuring continued compliance with life-safety regulations.