Wireless Insights
Carrier of Last Resort: Why Your Building’s POTS Lines Aren’t Covered
Carrier of last resort obligations are state law, not federal, and they guarantee basic voice service rather than the copper it rides on. Here is what that actually leaves protecting the analog lines in your building.
Talk to a POTS Replacement SpecialistThe rule everyone assumes is holding their lines up
Ask a facilities director what happens if the phone company walks away from the analog lines in their building, and the answer usually arrives with real confidence: they can’t, somebody has to provide service. That belief has a name. It is the carrier of last resort obligation, and it is the quietest load-bearing assumption in the POTS replacement conversation.
It is also a state rule, not a federal one. There is no national carrier of last resort statute. There are roughly fifty separate answers set by state legislatures and public utility commissions, and a meaningful number of those answers are now some version of “no longer.” The federal proceedings that get the headlines decide how a carrier exits. The state proceedings decide whether anyone was ever required to stay.
Short answer: A carrier of last resort obligation guarantees basic voice service inside a territory. It does not guarantee copper. Commissions are deliberately rewriting these rules to be technology neutral, which means a carrier can remain your carrier of last resort and still retire the copper pair feeding your fire panel. Eight states and the District of Columbia have eliminated the obligation outright, 13 more apply it only where competition exists, and 21 states are pushing to scrap or rewrite what remains.
What a carrier of last resort obligation actually requires
The National Regulatory Research Institute describes the obligation in four parts. A designated carrier must serve all customers who request service inside its territory, including extending facilities where that is necessary. It must obtain state or federal approval before withdrawing service. It must charge just and reasonable prices. And it must, in the language regulators have used for a century, exercise its calling with adequate care, skill, and honesty.
What gets delivered under that obligation is “basic service,” and every state defines the term itself. California’s definition runs to nine mandatory elements: voice-grade calls over the public switched telephone network or a successor network, free access to 911 and E911, directory services, operator services, telephone relay service, toll-free access, and Lifeline rates for eligible customers, among others.
Read that list again with a building in mind rather than a household. It describes a person picking up a handset. It says nothing about an alarm panel seizing a line at 2 a.m., a Centrex arrangement behind a switchboard, or the 40 analog circuits a mid-sized campus is still paying for. Scope varies by state: many statutes are written around residential and single-line business service, while California’s rulemaking record describes an obligation to serve residential and business customers alike. The one thing consistent across all of them is that basic service is a dial tone standard, not a life-safety standard.
The obligation covers service, not the copper it used to ride on
This is the part that surprises people, and it is the reason a surviving carrier of last resort rule is thinner protection than it sounds. The obligation attaches to the service. It does not attach to the facility.
Regulators are being explicit about it. When the California Public Utilities Commission opened its carrier of last resort rulemaking, R.24-06-012, in June 2024, the second issue in the scoping memo was technology neutrality for voice-grade connections. The commission is not asking whether copper should be preserved. It is asking what a voice-grade connection has to do, regardless of what carries it.
You can watch the same logic play out in the settlement talks. In February 2026, the CPUC’s Public Advocates Office described a joint proposal with AT&T under which the carrier would deploy more than one million new fiber lines in California as a condition of carrier of last resort relief in eligible areas. Fiber for copper, obligation traded for buildout. Whatever one makes of the bargain, note what is not on either side of it: the copper pair currently running your elevator phone.
So there are two separate exits, and both are open. A carrier can seek relief from the state obligation. Or it can keep the obligation, retire the copper, and satisfy the obligation some other way under the federal discontinuance rules. Our line-by-line breakdown of the FCC copper retirement order covers the federal half of that.
The map already has holes in it
Carrier of last resort protection is not a national floor that is starting to crack. It is a patchwork that has been thinning for two decades, and where you sit on the map decides what you have.
The clearest nationwide picture is still the National Regulatory Research Institute's survey of state obligations, published in July 2016 as Report 16-06. Treat the state lists below as the 2016 baseline rather than today's tally. Every current in the decade since has run the same direction, toward fewer obligations and narrower ones, so a state that has moved has almost certainly moved toward the bottom of this table rather than the top. Confirm your own state with its commission before you rely on it.
| Status as of the 2016 NRRI survey | Where | What it means for an analog line |
|---|---|---|
| Eliminated | Arkansas, Connecticut, Delaware, Florida, Montana, New Mexico, North Dakota, Tennessee, and the District of Columbia | No designated carrier is obligated to provide basic service on request. Continued service is a commercial decision. |
| Limited to competitive areas | Alabama, Colorado, Georgia, Idaho, Indiana, Kansas, Kentucky, Michigan, Mississippi, Missouri, North Carolina, Oklahoma, and Virginia | The obligation survives only where the commission has not found effective competition. Colorado released carriers in wire centers deemed effectively competitive as of July 1, 2016. |
| Under active repeal or rewrite | 21 states as of April 2025, per USTelecom. Utah has already passed legislation; Illinois, Colorado, and Minnesota were advancing measures. | Today’s answer may not be next session’s answer, and facilities budgets are built on multi-year cycles. |
| Phased by locality | Maine, on a city-by-city basis beginning in 2017 | Two buildings in the same portfolio, in the same state, can have different answers. |
Meanwhile the constituency for the rule keeps shrinking, which is the argument carriers make in every one of these proceedings. USTelecom put copper users at roughly 7 to 8 percent of the population in April 2025. The FCC’s own March 2026 fact sheet on the Network and Services Modernization Order counted 79 percent of fixed voice connections as interconnected VoIP as of December 2024, and 76 percent of adults living in wireless-only households. Nobody writes a protective rule for a shrinking group and then funds it generously.
California is the loudest case, not the safest one
California is worth walking through because it is the state where the fight has been most public, and because the outcome there is frequently misread as reassurance.
AT&T filed application A.23-03-003 in 2023 seeking relief from its carrier of last resort obligation. The CPUC rejected it on June 20, 2024, and the story traveled as a win for landline customers. What traveled less well is what the commission did in the same breath: it opened R.24-06-012 to rewrite the rules the application had been measured against. The assigned commissioner issued the scoping memo on February 4, 2025. Workshops followed in Middletown and Los Angeles that April and virtually in August 2025, alongside a public participation hearing. Under Public Utilities Code section 1701.5, the proceeding carries an 18-month clock, with a deadline of June 20, 2026.
Alongside it, AB 470 has moved through the 2025 to 2026 legislative session, and by February 2026 the Public Advocates Office was describing a joint proposal with AT&T rather than an opposition posture. A denial in 2024 bought time. It did not buy a permanent obligation, and no reasonable reading of that record supports planning a 2030 copper strategy around it. The same pattern is visible in AT&T’s $19 billion California modernization commitment and its June 2027 POTS retirement timeline.
What none of it covers: the lines that are not people
Here is the practical problem. Basic service is defined around a subscriber making and receiving calls. The analog lines that actually keep a facility operating are mostly not doing that.
- Fire alarm communicators, which answer to NFPA 72 and to the authority having jurisdiction, not to a state commission’s basic service definition
- Elevator emergency telephones, which answer to ASME A17.1 and to the elevator inspector
- Intrusion and access control panels, which answer to an insurer and a monitoring contract
- Gate and callbox intercoms, blue light phones, and area of refuge stations
- Pump station and building automation dialers that call a technician before they call anyone else
No carrier of last resort rule in any state promises that a fire alarm communicator will still reach its monitoring center, or that an elevator phone will still satisfy the code official who signs off on the next inspection. Those obligations sit with the building owner and they do not move when a tariff changes. If a line fails an inspection, the fire watch, the citation, and the liability are yours. We break the code side of this down in NFPA 72 requirements for POTS lines.
Which produces an uncomfortable symmetry. The strongest carrier of last resort state in the country still leaves the circuits you care most about outside the protection, and the weakest states leave everything outside it.
Plan against the earliest exit, not the friendliest one
The useful posture is not to work out whether your state still has an obligation. It is to assume the obligation will not be what saves the line, and to sequence the work accordingly.
- Inventory before you negotiate. Most organizations cannot produce a current list of their analog lines, which circuits ride them, and which building each one terminates in. Our POTS line replacement checklist is built for exactly that pass.
- Find the wire center, not just the address. Retirement happens by wire center, so two buildings a mile apart can be on different clocks. The free POTS wire center shutdown tracker is the fastest way to check.
- Rank by consequence of failure, not by cost per line. The $70 line running a fire alarm communicator outranks the $400 line running a break room fax.
- Read the notice period as a build window. Ninety days of notice is not ninety days of project time once procurement, site survey, and inspection are in the path.
- Treat the state proceeding as intelligence, not insurance. Docket activity tells you what a carrier intends. It does not commit the carrier to your building.
A managed POTS line replacement takes the question off the regulatory calendar entirely. RCN’s POTS Link consolidates up to eight analog lines onto a single managed cellular device with 24 hours of battery backup, multi-carrier access across AT&T, Verizon, and T-Mobile, remote line-status monitoring, an in-house install team, and 24/7 NOC support. If you want the mechanics rather than the policy, start with the plain-English technical explainer.
Your copper timeline is not on a docket you control
RCN has moved analog lines off copper for school districts, city governments, universities, and public housing authorities, including a Texas university deployment covering 75 lines. Tell us what is in your buildings and we will tell you what has to move first.
Talk to a POTS Replacement SpecialistFrequently asked questions
What is a carrier of last resort obligation?
A carrier of last resort obligation requires a designated telephone company to provide basic voice service to any customer who requests it inside a defined territory, to charge just and reasonable rates, and to obtain regulatory approval before withdrawing service. It is created by state law and administered by state public utility commissions, so the scope and the exceptions differ in every state.
Does a carrier of last resort obligation require the carrier to keep copper lines in service?
No. The obligation attaches to the service, not to the facility. State commissions are explicitly moving toward technology-neutral definitions of a voice-grade connection, which means a carrier can remain the designated carrier of last resort and still retire the copper pair serving your building, provided it satisfies the obligation another way.
Which states have eliminated carrier of last resort obligations?
The National Regulatory Research Institute's July 2016 nationwide survey found the requirement eliminated outright in Arkansas, Connecticut, Delaware, Florida, Montana, New Mexico, North Dakota, Tennessee, and the District of Columbia, and limited to areas without effective competition in 13 more states including Alabama, Colorado, Georgia, Idaho, Indiana, Kansas, Kentucky, Michigan, Mississippi, Missouri, North Carolina, Oklahoma, and Virginia. That is a 2016 baseline, not a current tally. The direction of travel since has been consistent: as of April 2025, USTelecom counted 21 states pursuing further repeal or modernization. Confirm your own state with its public utility commission.
Does the obligation cover fire alarm, elevator, and alarm circuits?
Not in any meaningful way. Basic service is defined around a subscriber placing and receiving voice calls, with 911 access, directory service, operator service, and relay service attached. It does not speak to whether a fire alarm communicator reaches its monitoring center or whether an elevator telephone satisfies ASME A17.1. Those obligations stay with the building owner and the authority having jurisdiction.
The CPUC rejected AT&T’s request in June 2024. Does that settle it for California?
No. The CPUC denied application A.23-03-003 on June 20, 2024, and in the same period opened rulemaking R.24-06-012 to rewrite the carrier of last resort rules themselves. The scoping memo issued February 4, 2025, and the proceeding carries a statutory deadline of June 20, 2026. By February 2026 the Public Advocates Office was describing a joint proposal with AT&T tied to more than one million new fiber lines.
How should we plan if our state still has a carrier of last resort rule?
Plan against the earliest credible exit rather than the most favorable one. Inventory every analog line and the circuit riding it, identify the serving wire center for each building, rank the lines by consequence of failure rather than monthly cost, and move life-safety circuits first. Treat state docket activity as intelligence about carrier intent, not as a guarantee about your building.
Speak with a Connectivity Expert
Speak with a POTS Replacement Specialist about replacing your CenturyLink lines before the next notice arrives.
Want to Learn More?
Request a custom quote.