They're Switching Off the Copper Landline: What Else in Your House Was Using That Line

The letter turns up looking like junk mail, which is the first problem with it. Something about network modernisation, an upgrade, a date. Most people read the first paragraph, decide it is a sales pitch, and put it on the pile by the kettle.

It is not a sales pitch, or at least not only one. Across a large part of Southern California the copper telephone line that has come into the house for the last fifty or sixty years is genuinely being switched off, and there is a date attached to it. What nobody tells you — not the letter, not the news story, and certainly not the companies advertising a replacement box — is that the phone is rarely the thing you will miss. The phone is the visible part. What actually causes trouble is the set of quiet, unglamorous devices in the house that were using that same pair of wires without anyone thinking about it, most of which fail in a way you will not notice for months.

So this is not a guide to which phone service to buy. It is a guide to working out what you have got, what stops when the copper goes, and what to ask before you agree to anything. We do not sell phone service and we get nothing whichever way you go.

What is actually happening, without the press release

On 20 May 2026 AT&T filed applications with the Federal Communications Commission to discontinue its legacy copper-based voice service — residential local service and business access line service — across portions of 360 wire centres in California. The California Public Utilities Commission, which is tracking the filings, puts the scope at approximately 184,000 residential customers and 15,000 business customers, with AT&T proposing to stop providing the service on or after 1 June 2027.

A "wire centre" is the building your copper pair physically runs back to, so the affected areas are drawn along old telephone-network boundaries rather than city lines. Two houses on the same street can land differently, which is exactly why the individual notice matters. As the CPUC puts it, "Impacted Californians are federally required to receive a notice from AT&T." If you have not had one, you are not on the current list — but that is a statement about today, not about 2029, because AT&T has said publicly that it intends to exit copper across the majority of its wireline footprint by the end of that year.

The same company filed something else on the same day, and it is the piece that tells you how contested this is. In a Petition for Preemption and Declaratory Ruling — WC Docket No. 26-125, released for comment by the FCC's Wireline Competition Bureau on 22 May 2026 — AT&T asked the Commission to declare that "any California law or regulation that interferes with or otherwise conditions AT&T's ability to discontinue [Plain Old Telephone Service (POTS)] as authorized by the Commission is preempted." In plain English: AT&T wants the federal approval to override the state rules that currently sit on top of it.

If your line is with a different carrier the filings and dates differ, but the walk round the house below does not change at all.

The letter is not the last word, and almost nobody says so

This is the single most useful thing in this article, so it goes near the top.

In California, AT&T is what the regulator calls a Carrier of Last Resort — in the CPUC's own words, "a telecommunications company that is required to offer basic telephone service to anyone who asks for it in a certain area — no matter where they live or what their income is." AT&T asked to be released from that obligation in 2024. The CPUC said no.

That is why the letters read more definitively than the legal position warrants, and why organisations that represent local government have been telling their members so. The California State Association of Counties described the disconnection notices to its members as "not definitive," adding that they "do not change AT&Ts legal responsibility as a COLR to provide basic, reliable telephone services to anyone who asks for it."

Hold two things in your head at once, because both are true. The copper is going — that part is real, and treating the letter as junk mail is a mistake. But "the copper is going" and "you have no say in what replaces it" are different claims, and only the first one is established. Basic service in California is deliberately technology-neutral; the CPUC's standards are about what the service must do — voice calls, free 911 access, directory assistance, relay services, protections against unauthorised charges — not about what it runs on. Whether the federal preemption petition changes that is being argued right now, and this article will be out of date on that point before it is out of date on anything else. If it matters to your household, the CPUC's Public Advisor's Office exists precisely for this and can be reached at 1-866-849-8390 or public.advisor@cpuc.ca.gov.

Now go and walk the house, because this is the part that bites

Get up and physically follow the phone wiring. You are looking for anything plugged into a telephone jack — the small square socket with the clip, not the round coaxial one and not Ethernet. In an average house we find between two and six things, and the householder had forgotten about at least half of them.

The list, in roughly the order they cause trouble: a monitored burglar or fire alarm panel, usually in a hall cupboard or the garage; a medical alert base station, usually in a bedroom or the living room; a fax machine or a multifunction printer with a fax section, in a home office; a gate intercom or entry callbox at the end of the drive; a DSL modem, if the internet also arrives on that copper; and the cordless phone base with the answering machine built into it, which is the one everybody thinks of and the least important of the six.

Write down what you find, with the make and model where you can see it, before you speak to anybody. Every single conversation you are about to have goes better if you can say "there is a monitored alarm panel and a medical alert base on this line" at the start of it rather than discovering it afterwards.

The alarm panel is the one that fails silently

An older monitored alarm reports to its central station by dialling out over the phone line. It does this when it is tripped, and it does it on a schedule to prove it is still alive. Cut the line and the panel does not stop working — the siren still sounds, the keypad still beeps, the lights on the front still look exactly as they always did. What stops is the part you are paying for, which is somebody at the other end being told.

That is the failure mode to be frightened of, and it is the same shape as every other silently-failing device we get called about: the thing looks fine, so nobody investigates, and the gap is only discovered at the worst possible moment. An alarm that cannot report is an expensive siren.

The fix is not a network fix and it is not ours. It is a call to your alarm company, and the question is specific: "my telephone line is being retired — is this panel on a cellular or IP communicator, and if not, what does it cost to add one?" Most panels of any age can take a cellular radio module. Some very old ones cannot and want replacing. Either way, you want that answered in the months before the cutover, not the week after, because every other customer of that alarm company in your area is going to ask the same question at the same time.

Two things worth knowing while you are on the phone to them. AT&T's own guidance for customers moving to its digital phone service says the technician will configure the wiring so the phone line is hard-wired directly to the alarm panel — but it also puts the burden squarely on you: "You are responsible for testing your home alarm system with your alarm company after installation of Phone is complete, and on an ongoing basis." Take that literally. Book the test, do it while the installer is still findable, and put a repeat in the calendar.

The medical alert base, and why this one deserves a phone call today

A medical alert pendant talks to a base station in the house, and an older base station talks to its monitoring centre over the landline. Same silent-failure problem, higher stakes, and frequently in a household where nobody is going to notice a change in a dial tone.

The good news is that this is the easiest of the six to solve, because the industry moved years ago. Cellular medical alert bases are now the standard product rather than the exotic one, they do not need a home phone line at all, and most providers will swap the equipment for an existing subscriber. Call the monitoring company, tell them the landline is going, ask for the cellular unit, and — this is the part people skip — ask them to run a test alarm once it is installed, with you standing there.

If the person who wears the pendant is not the person reading this, make the call for them and write the date of the equipment swap on the fridge. In our experience this is the device most likely to be left until it is genuinely too late, because it is the one nobody touches from one year to the next.

Fax lines, card machines and the gate: the small-business version

If you run a business, the copper line is often carrying more than you think, and the replacements are documented as being fussier about it than the sales conversation suggests.

AT&T's own device documentation for its wireless home phone bases — the small boxes that give you a dial tone over the cellular network — is unusually blunt about this. It states that the device is not compatible with home security systems, fax service, medical alert systems, medical monitoring systems, credit card machines, IP/PBX phone systems, or dial-up internet. That is not a warning buried in a manual nobody reads; it is the compatibility list, and it rules out most of the reasons a small business still has a copper line.

The newer AT&T Phone – Advanced product is a different thing and is not subject to that list — AT&T supports connecting fax, alarm and medical monitoring equipment to it, and directs customers to its care team to get it done. But note the shape of the guidance even there: connect it, then confirm with your own monitoring provider that the service is actually operating. Nobody at the phone company is going to test your fire panel for you.

So the rule for every device on the list is the same, and it is worth saying out loud before you sign anything: do not assume, ask specifically about your device by name, and test it afterwards yourself. "It works just like a landline" is a marketing sentence, not a compatibility statement.

And for the fax specifically, it is worth asking whether you need one at all. A great many small offices keep a fax line alive for two or three incoming pages a month from one insurer or one lab, at a cost that has quietly become absurd. An internet fax service that delivers to email costs a fraction of it and removes a device from this list permanently. That is a change we can help you make properly — including keeping the existing number — rather than one you should discover in a panic the week the line goes dead.

The rule that made them offer you a backup battery expired in September 2025

Here is the part that no article on this subject seems to mention, and it is the one with the most practical consequence for a Southern California household.

For about a decade there was a federal rule requiring providers to sell you backup power for exactly this situation. It lived at 47 C.F.R. § 9.20, and it defined a "Covered Service" as "any facilities-based, fixed voice service offered as residential service, including fixed applications of wireless service offered as a residential service, that is not line powered" — which is a precise description of every product being offered as a copper replacement. Providers had to offer, at the point of sale, "at least one option with a minimum of eight hours of standby backup power," and from February 2019, an option with a minimum of twenty-four hours as well. The backup had to cover all the provider-supplied equipment on the premises that must stay powered for the service to reach 911. And there was a disclosure list attached to it: the provider had to tell each subscriber what the service could and could not do with and without backup power, the expected duration, the purchase and replacement cost, storage conditions, self-testing instructions, and the warranty terms.

Paragraph (g) of that section reads: "The requirements of this section shall no longer be in effect as of September 1, 2025." The section is now marked [Reserved] in the Code of Federal Regulations. It is gone.

Sit with the timing for a second. The rule that obliged a provider to offer you a battery, and to explain in writing how long it would last, lapsed roughly nine months before the filings that switch off the self-powered thing it was written to replace. Nothing about that is a scandal — sunset clauses expire all the time — but it does change what you have to do. Nobody is now required to raise the subject with you. You have to raise it with them.

Which is why the copper felt different: it powered itself

The old line was not powered from your house. It carried its own low-voltage supply from the telephone exchange, over the same pair of wires that carried the call, from a building with batteries and generators in the basement. That is why a plain corded phone worked in a blackout when everything else in the house was dark, and it is why the copper line has been quietly propping up the emergency plan of a great many households that never wrote one down.

Every replacement moves that power problem into your hallway. A cellular home phone base is a device plugged into a wall socket. A voice service riding on your internet depends on a modem or fibre ONT, a router, and possibly a mesh node — three or four things plugged into wall sockets. When the grid drops, all of them stop instantly unless you have done something about it.

AT&T does say that its Phone – Advanced units have battery backup, and the ones we have seen have a user-replaceable battery, which is genuinely better than nothing. But "has a battery" is not a plan, for two reasons. First, the runtime is hours, and Southern California's characteristic outage is not four hours, it is a public safety power shutoff that can run into days. Second, a battery in the phone box does nothing for the router, so if your voice service runs over the internet rather than over cellular, the phone box can be perfectly charged and still have nothing to talk to.

The good news is that the fix is small and cheap and we have written it up in detail separately: the whole internet side of a house draws about as much power as a light bulb, so a modest uninterruptible power supply under the desk carries the modem and router for hours, and a portable power station carries them for days. If you are going to be asked to give up a self-powered phone line, that is the thing to spend the money on, and it protects your Wi-Fi, your cameras and your work-from-home setup at the same time.

If the internet was on that copper too

Plenty of the affected addresses are DSL, and DSL is copper by definition. AT&T has been clear that copper broadband goes with copper phone, and the replacement on offer will be fibre where it has been built, and a fixed-wireless product where it has not.

Fibre, if you can get it, is a straightforward upgrade and the only real caution is a boring one: the box on the wall becomes an ONT that belongs to the provider, so any plan you had to buy your own modem stops applying. Fixed wireless is a bigger change than it looks. It is a cellular connection with a different name, which means the box has to live where the signal is rather than where you want the Wi-Fi, and it comes with a quirk that catches people out — you will generally not have a real public address on the internet, which breaks remote access to home cameras and some work VPNs. We have written both of those up in full, because they are the two questions we get asked most after a switch of this kind.

The practical advice is the same either way: sort the internet replacement out before the cutover date rather than after, because if voice ends up riding on that connection, the order in which you do these two jobs decides whether you spend a week without either.

A year-long transition delivered by phone call is a gift to scammers

AT&T has said it contacts affected customers repeatedly over roughly a year — by letter, email, SMS and phone call. That is a reasonable thing for a company to do. It is also, from a fraud point of view, close to a perfect setup: a real, widely reported, slightly frightening change, a deadline, and an established expectation that your phone company will ring you out of the blue about it.

We have not seen a specific campaign built on this in our own service area, and we are not going to invent one. But the pattern is entirely predictable, so here is the defence, which costs nothing and works against every version of it.

Never act on a number, a link or a payment request that arrived in the contact itself. If somebody calls, texts or emails about your landline transition, thank them, hang up, and start again from a source you already had — the number printed on your bill, the address you already use to sign in, or a company page you navigated to yourself. Nothing legitimate about this transition requires you to act inside a single phone call. There is no version of it where a genuine representative needs a gift card, a wire transfer, a code read back off your phone, or remote access to your computer. And be especially wary of anyone offering to "protect" your existing service for a fee, or claiming your alarm or medical alert will be disconnected today unless you pay — the real timeline is measured in months and comes with a written date.

One legitimate lever worth knowing about, precisely because it is the sort of thing an impostor would never mention: if you believe you are being pushed off a service you depend on, you can file a complaint with the CPUC. The California State Association of Counties pointed its members at exactly that route, online or on 1-800-649-7570.

Two things people worry about that are usually fine

Your number. Keeping the same telephone number through this is normal and expected, not a favour. Ask the question explicitly and get the answer before the switch rather than after, but do not let the fear of losing it push you into a decision.

Your 911 access. Free access to 911 is part of the basic-service standard the CPUC applies regardless of the technology underneath, and it is the one thing every party in this argument agrees on. What does change is how the service knows where you are. A copper line was tied to an address by definition; a replacement box has to be told. So when whatever replaces it is installed, check that the service address on the account is the address the box is actually sitting at — a detail that goes wrong most often for people who moved the equipment to a different room, a garage office, or a second property.

What to do, in order, if a letter has arrived

One: read it properly and write down the date. Everything else is scheduling.

Two: walk the house and list every device on a phone jack, with makes and models. Ten minutes, and it is the step that prevents every expensive surprise later.

Three: call the alarm company and the medical alert company first, before the phone company. They are the two with the longest lead times and the worst failure modes, and their answers may change which replacement service suits you.

Four: decide what happens to the fax, if there is one. Often the answer is that it goes away entirely and nobody misses it.

Five: sort out the internet side, and sort out backup power at the same time — one uninterruptible power supply under the desk, keeping the modem and router alive, is the single highest-value thing you can buy out of this whole exercise.

Six: after the switch, test everything that matters, with the monitoring companies on the line. An alarm test and a medical alert test take five minutes each and are the only way you will ever find out whether the transition actually worked.

Seven: if you genuinely depend on the line and you are not being offered something that works, the CPUC route above exists. Use it rather than assuming the letter has settled the matter.

How we can help — and what is not ours to do

The honest boundary first. We do not sell phone service, we are not an alarm company, and we do not touch the monitoring contract on a medical alert or a fire panel. Those calls are yours to make, and any company that tells you otherwise is selling you something.

What we do is the house side of it. Working out what is actually plugged into that line and what each thing needs. Getting the internet replacement installed somewhere sensible rather than wherever the box landed, so the Wi-Fi still reaches the back of the house. Putting the modem, router and any voice equipment on battery backup so a shutoff does not take the phone with it. Moving a fax off a dedicated line and onto something that delivers to email, number intact. Making sure a smart doorbell, a camera or a gate intercom that used to lean on the old line comes back properly afterwards. And being the person who checks, a fortnight later, that the things you were told would work actually do.

We cover homes and small businesses across Southern California. If a letter has arrived and you would rather not work out on your own which of the boxes in your house it affects, send us a photo of the letter and a list of what is plugged into the phone jacks — that is usually enough for us to tell you over the phone whether this is a half-hour job or a real project.