POTS Line Replacement for Dental Offices: What to Do Before the Copper Phone Lines Shut Off

The letter from the phone company is sitting on the front desk. It says the copper lines at your address are being retired and that service may end on or after a date a few months away. Someone has to work out what still runs on those lines before then, and in most dental offices that job lands on the office manager. The front-desk phones are the obvious part. The fax line the lab still uses, the alarm panel in the back closet and the card terminal at checkout are the parts that get missed.

This guide gives you the dated facts from FCC filings, a table for finding every copper line in a dental office, the replacement options, a fax decision table for patient records, a 30–60–90-day plan with number porting, and the questions to ask before you sign anything.

What is a POTS line, and why is yours going away?

A POTS line ("plain old telephone service") is an analog phone line delivered over a pair of copper wires from the phone company's central office. Carriers are retiring those copper networks and moving customers to fiber, cable, fixed wireless or mobile service, so the copper line on your wall will eventually stop working even if nothing in the office changes.

Two terms come up in every carrier letter and quote:

• • PSTN (the public switched telephone network) is the worldwide network that connects ordinary phone numbers to each other. A copper POTS line is one way into it; a VoIP service is another.
• • VoIP (voice over internet protocol) carries calls as data over an internet connection. It reaches the same PSTN, so patients still dial the same kind of number.

The FCC calls this the "tech transition" and says providers "will retire aging copper‑line networks" where fiber, wireless and satellite replacements exist, in its tech transition guide for consumers and small businesses. The same page lists devices to check for compatibility, and three sit in most dental offices: security and alarm systems, fax machines and credit card machines.

VoIP vs landline: what actually changes in the office

The table is the reason a "simple phone switch" turns into a small project. The voice calls move easily, and our overview of dental office phone systems and VoIP covers that part. The devices that send signals over a phone line, rather than voices, need their own plan.

Are copper phone lines going away for dental offices? The dated timeline

Yes, in stages that depend on the carrier and the wire center that serves your building. In March 2026 the FCC adopted rules that make it faster for carriers to stop offering copper voice service, and AT&T has filed to discontinue copper-based business and residential lines in parts of many states. Your carrier letter gives the date for your address.

The table lists what the primary documents say, as of October 2026. Dates in carrier filings are written as "on or after", which means the carrier may stop the service from that date, not that every line goes dark that day.

How much notice do you get?

Less than many offices expect. The FCC's order says carriers must "notify customers of their applications to discontinue service, which must be done no later than the date they file their applications." Once the FCC puts an application on public notice, customers have a short window to object, and a streamlined application is granted automatically on the 31st day unless the FCC acts.

The order also gives carriers blanket authority to "grandfather" legacy voice service, which means they can stop selling it to new customers while existing customers keep it for a period. If your office is moving or opening a second location, assume a new copper line will not be offered.

What in a dental office still uses a POTS line?

More than the phones. In a typical dental office the copper lines may also carry the fax, the burglar alarm's dialer, the fire alarm panel, an elevator emergency phone, an older card terminal or postage meter, and sometimes DSL internet. Each needs its own replacement and owner, and the phone company will not know which device sits on which line.

Use this table as the worksheet for the inventory. "Who handles it" names the party that has to approve or install the replacement.

How to find every line in one afternoon

1. 1. Get the bill. Ask the carrier for a customer service record (CSR) that lists every number and line on the account, including lines nobody remembers.
2. 1. Walk the office with the list. Follow each phone cord from the device to the wall jack, and from the phone closet back to the demarcation point where the carrier's wires enter.
3. 1. Call each number. Ring every line on the CSR and note what answers: a handset, a fax tone, silence (often an alarm panel), or nothing at all.
4. 1. Ask the building. In a leased suite the landlord may own the elevator phone, the fire panel or the line into the building.
5. 1. Write down the owner. Put a name next to each line before any quote is accepted.

If the office is also planning new cabling or a secure dental office network design, do the inventory first; it changes how many network ports and which closets the new equipment needs.

What are the POTS replacement options?

There are five practical options, and most dental offices combine two or three: VoIP for calls, cloud fax for patient records, a cellular or IP box for alarms and elevator phones, digital voice over the carrier's own fiber or cable, and keeping a copper line for as long as the carrier allows it.

POTS replacement for voice: what to look for

For the main numbers, the questions that matter in a dental office are about the front desk, not the features list: how calls ring during a busy hour, how the after-hours greeting and answering-service forwarding are set, and whether caller ID can open the patient record. Our guide to phone integration with Dentrix, Eaglesoft and Open Dental covers screen pops and call logging.

POTS replacement for devices: the adapter question

An analog telephone adapter (ATA) turns a network connection into a phone jack for an old device. For Microsoft Teams Phone, for example, Microsoft Learn's page on connecting analog devices says "you must use an Analog Telephony Adapter (ATA)" supported by the certified session border controller vendor, and lists fax machines among analog devices. An adapter makes a device work in principle; only a test proves it on your line.

How do you replace the fax line and still send patient records safely?

Move the fax to a cloud fax service that signs a business associate agreement (BAA), or keep a tested adapter line only for the few senders that need it. HHS allows faxing patient information for treatment with reasonable safeguards, and HHS treats a cloud service that stores that information as a business associate.

Fax still matters in dentistry. Lab prescriptions, insurance attachments, referral letters and hospital records can still arrive and leave by fax, and practice software allows for it: Open Dental's prescription window, for example, lists "Faxed" among its send-status options, according to the Open Dental manual page on prescriptions.

What HHS says about faxing patient information

HHS answers the basic question directly. In its FAQ on sharing patient information for treatment by fax, e-mail or phone, it says providers may share protected health information for treatment "as long as they use reasonable safeguards when doing so," and gives fax examples: confirming a fax number that is not regularly used, and pre-programming frequently used numbers to avoid misdirected faxes.

For cloud fax, the relevant HHS document is its guidance on HIPAA and cloud computing. It says a cloud service provider that creates, receives or maintains (for example, processes or stores) electronic protected health information for a covered entity is a business associate, and that the "conduit" exception is limited to transmission-only services with no more than temporary storage. A fax service that keeps your faxes in an online inbox stores them. Ask your counsel or compliance lead how this applies to the service you choose.

Fax decision table

T.38 is the ITU-T recommendation for real-time Group 3 fax over IP networks. It exists because fax tones were designed for an analog circuit; whether a given fax gets through depends on your provider, the sender's provider and everything between them supporting it.

Three dental scenarios to test before cutover

• • The dental lab. If your lab accepts or returns prescriptions by fax, send a test Rx form with no patient details from the new service and ask the lab to fax one back. Check that it arrives legible, in the right inbox, and that someone is assigned to watch that inbox.
• • The insurer. If a payer asks for narratives, X-ray reports or claim attachments by fax, send a multi-page test to a number that confirms receipt, and keep the confirmation with the claim.
• • The hospital or specialist referral. If a hospital records department or an oral surgeon sends long documents by fax, ask one to send a test, and confirm that the cloud fax inbox does not split, drop or delay large faxes.

What happens to the alarm, fire panel and elevator phone?

They move to a cellular or IP communicator chosen and tested by the company that monitors them. The fire alarm is the strictest case: NFPA 72 sets the requirements for fire alarm signaling, and your local fire marshal, the authority having jurisdiction (AHJ), decides what communicator and pathways are accepted for your building.

Do not let a VoIP installer move the alarm or fire panel onto the new phone system as a side task. The alarm industry asked the FCC to require replacement services to carry alarm signals with a specific codec setting "end-to-end through all carrier handoffs," and the FCC declined in paragraph 31 of its March 2026 order. In plain terms, the order does not require the carrier to prove that your alarm works on the replacement service, so ask your alarm company to test it.

Fire alarm panel

NFPA 72, the National Fire Alarm and Signaling Code, is the standard fire alarm designers, installers and authorities having jurisdiction work from; which edition and how many communication paths apply depend on your jurisdiction. Ask the fire alarm company to confirm in writing which communicator they will install, that it is accepted by the AHJ, and when the test signals to the monitoring station will be run.

Burglar alarm, cameras and door entry

Ask the alarm company whether your panel needs a new cellular or IP communicator or a new panel, and what monitoring changes. If door entry, cameras or access control share a line or the network, include them; our page on access control and camera installation for dental offices covers the network side of those systems.

Elevator emergency phone

If your office is in a building with an elevator, the emergency phone inside the car may be on a copper line the landlord pays for. Ask the building manager who owns it and what the replacement plan is.

How do you keep your phone numbers when you switch?

You port them. Number porting moves a phone number from the old carrier to the new provider so patients keep dialing the same number. The new provider starts the port with a signed Letter of Authorization (LOA) and a copy of your customer service record; you keep the old service active until the port completes.

The FCC's guide to keeping your phone number when you change providers sets out the basics: you can keep your number when you stay in the same geographic area; do not terminate service with the old company before starting service with the new one; the old company "cannot refuse to port your number, even if you owe money"; and FCC rules require simple ports to be processed in one business day. A dental office with several lines and a fax number is often not a simple port, so allow more time.

What can delay a port

• • Mismatched details. The name, service address and account number on the LOA must match the old carrier's records exactly. Copy them from the CSR, not from memory.
• • Missing numbers. A number that is on the account but not on the port request may be disconnected when the old account closes. Port the fax number and any marketing or tracking numbers too.
• • A PIN or passcode. Some carriers require an account PIN to release numbers.
• • Cancelling too early. If the office cancels the old service before the port completes, the number can be lost.

How will you know when your number has been transferred?

The new provider gives you a port date and, usually, a confirmation when the port completes. On that day, call each ported number from a mobile phone and check that it rings on the new system, that the fax number answers with a fax tone on the new service, and that caller ID shows the practice name.

What is the 30–60–90 day plan from the carrier letter to cutover?

Inventory in the first 30 days, choose and order in the next 30, and port, test and cut over in the last 30, with the old lines left active until each replacement is proven. If your letter gives less than 90 days, compress the steps but keep the order: inventory first, life-safety lines tested before any copper line is cancelled.

Schedule the port for the quietest hour of the week, and tell the front desk what to do if a line does not ring. Keep the inventory table after cutover; it helps the next time the office moves or adds a location, as our guide to planning IT for a second dental office or relocation explains.

What happens to the phones in a power or internet outage?

A copper line carries power from the phone company, so a corded phone on it may keep working when the office loses power. VoIP and carrier digital voice need power at the office and a working connection. Plan battery backup for the network equipment and phones, and a cellular failover so calls and alarms still get out.

The FCC's tech transition page says network upgrades "may mean your phone won't work during a power outage unless you have a backup power source," and that backup batteries must be tested, monitored and maintained.

Add the phones to your outage routine. Our checklist for what to do when the dental office internet goes down covers the first hour, the dental office storm and power plan covers battery time, and the server shutdown and UPS checklist covers shutting down safely.

Does 911 still work on the new phone system?

Yes, if the new system is set up correctly. Under Kari's Law, a multi-line phone system installed after February 16, 2020 must let staff dial 911 directly, without a 9 or other prefix, and must notify a central location, on site or off site, when 911 is called. RAY BAUM'S Act rules add location information to each call.

The FCC's page on 911 requirements for multi-line telephone systems says installers, managers and operators may not install or operate a system unless a user "may directly initiate a call to 911 from any station equipped with dialing facilities, without dialing any additional digit." Dispatchable location means the street address plus information such as a suite or similar detail needed to find the caller; in a multi-suite building, that is your suite number.

Ask the installer to show you before cutover that 911 dials directly from every handset, that someone is notified, and that the registered address includes the suite. Our page on VoIP services for dentists, including 911 and call recording covers how these settings fit into a dental phone setup.

What does POTS line replacement cost a dental office?

It depends on how many lines and devices you have, so price it by category rather than by a single number. The usual categories are phones and adapters, the VoIP and cloud fax subscriptions, alarm communicators, battery backup, internet upgrades, porting, installation labor and the old carrier's final bill.

Prices vary by vendor and region, so use the table to make sure every quote covers the same things.

The FCC porting guide notes that companies may charge for porting "but you can ask whether any fees can be waived or negotiated." Check the old contract for early-termination terms, and ask each vendor to state what is excluded.

What to ask your IT provider about POTS line replacement

Take these questions to your IT provider, your carrier and the VoIP vendor. Written answers make it easy to compare quotes and to hold each party to its part of the switch.

If staff call the IT helpdesk when a phone or fax stops working, ask how those tickets are logged; our page on dental computer support and helpdesk covers the support side.

How Legend Networking can help

Phone, fax and alarm lines sit on the same network and power as the rest of the practice's technology, so a copper shutdown is easier to plan with the people who already look after that network. The facts below are Legend Networking's own:

• • Practices: Served over 3,500 practices since 2004
• • New offices: 1,500+ dental startup buildouts
• • Engineering team: In-house engineers; no outsourced first-level triage
• • Monitoring and helpdesk: 24/7 monitoring, and a helpdesk staffed 24/7 at 1-800-794-1588
• • Google reviews: 4.8 rating · 173 Google reviews

This guide comes from Ian Lynch, who has 22 years in dental IT and oversees the NOC, onsite dispatch and client technology roadmaps. To see how phones fit into the wider support picture, read our guide to dental IT support for practices nationwide. If the phone change comes with new cabling or closet work, our guide to dental office network setup covers the order of work.