Most businesses that get an AT&T copper retirement letter think about one thing first: the main phone number. That part is usually simple. The number can be moved to a cloud phone system and customers never notice. The harder part is everything else plugged into a copper line: the alarm panel in the back room, the fax machine billing still uses, the emergency phone in the elevator, and the card terminal that still dials out.
The short answer: every device on a copper line needs its own replacement. Desk phones move to a cloud phone system. Fax moves to online fax. Alarm panels and elevator phones usually need a certified cellular or internet communicator, chosen with your alarm company or elevator contractor and approved by your local inspector. Start the inventory now, because AT&T has said it may begin shutting off copper service in affected parts of California on or after June 1, 2027.
In May 2026, AT&T asked the FCC for permission to stop offering traditional landline service in parts of 360 California wire centers, covering about 184,000 residential and 15,000 business customers. The FCC approved that request on June 29, 2026. AT&T has said it wants to begin turning off service as early as June 1, 2027.
California regulators are still pushing back. The California Public Utilities Commission opposes a separate AT&T request asking the FCC to override state copper rules, and AT&T is in court with the state over its obligation to keep providing landline service. Until those disputes are settled, state rules still protect landline customers. The direction is clear, though, and waiting until the last few months is how businesses end up with a dead alarm line or an elevator that fails inspection.
For the full timeline, see our AT&T landline shutdown guide for California businesses.
Pull your latest AT&T bill and list every phone number on it. Then walk the building and match each number to a device. Most offices find at least one line nobody remembered.
If a line has no obvious device, call the number while someone listens around the building. Write down the number, the device, the location and who services it.
| Device on copper | Typical replacement | Who to involve |
|---|---|---|
| Desk phones and main numbers | Cloud phone system with the same numbers ported over | Your phone provider |
| Fax machine | Online fax (faxes arrive by email), or a fax adapter on the phone system | Your phone provider |
| Burglar alarm panel | Cellular or internet alarm communicator | Your alarm monitoring company |
| Fire alarm panel | Listed cellular or IP communicator approved for fire signaling | Fire alarm contractor and local fire authority |
| Elevator emergency phone | Cellular or IP elevator communicator | Elevator contractor and building owner |
| Card terminal | Internet or cellular terminal | Your payment processor |
| Gate or door call box | Cellular or VoIP call box | Access control vendor |
Fax is the easiest one. Online fax keeps your existing fax number, delivers incoming faxes to email as PDFs, and lets staff send faxes from a computer. Medical offices, law firms and title companies that still receive records by fax usually find it faster than the old machine. If a specific device must keep working, such as a multifunction printer, an adapter on the phone system can connect it, though results vary by device.
Alarm panels were designed to call the monitoring center over copper. When the copper line goes away, the panel can no longer report a break-in or fire. Most monitoring companies now install a cellular communicator, a small radio that sends alarm signals over the cellular network. Some also use an internet connection as a primary or backup path. Call your alarm company early, because they schedule these changes and some older panels need upgrades.
Fire alarms have stricter rules than burglar alarms. The replacement must be listed for fire signaling and approved by the local fire authority that inspects your building. Work through your fire alarm contractor rather than swapping anything yourself, and keep the paperwork for your next inspection.
Safety codes require a working two-way emergency phone in passenger elevators, and inspectors test it. Elevator phones are often on a copper line nobody thinks about until inspection day. The usual fix is a cellular or IP communicator designed for elevators, installed by your elevator contractor. In multi-tenant buildings this is usually the building owner’s responsibility, so tenants should ask property management for their plan.
Many card terminals already support internet or cellular connections. Ask your payment processor whether yours does, or whether a replacement is available. Postage meters, gate call boxes and older building controls follow the same logic: check whether the device has an internet or cellular option before the copper line goes dark.
Do not cancel a copper line until the device on it has been replaced and tested. Cancelling early is the most common way an alarm or elevator ends up without a connection.
Supreme Call moves your phone numbers and fax lines off copper, installs the new phones on-site, and sets up online fax with your existing fax number. We also help you build the line inventory so your alarm company and elevator contractor know exactly which lines they need to replace. If you are comparing options, our guide to VoIP vs landline for small business covers the trade-offs.
If your alarm panel reports to the monitoring center over a copper phone line, it will stop reporting when that line is disconnected. Ask your alarm company to install a cellular or internet communicator and test it before the copper line is cancelled.
Yes. Online fax keeps your existing fax number. Incoming faxes arrive in your email as PDFs, and you can send faxes from a computer without a fax machine or a copper line.
In most multi-tenant buildings the building owner or property manager is responsible for elevator emergency phones. The replacement is usually a cellular or IP communicator installed by the elevator contractor.
AT&T has said it may begin ending copper landline service in affected parts of California on or after June 1, 2027. The FCC approved the request on June 29, 2026, while California regulators continue to challenge parts of the plan.
Only after every device on those lines has been replaced and tested. Cancelling a line before the alarm, elevator or fax replacement is working can leave important systems without a connection.
Supreme Call designs, installs and supports business phone systems for companies across Los Angeles and the San Fernando Valley. Plans run $19.99 to $24.99 per extension per month, with no installation fee and month-to-month service. Call (310) 444-1500 or book a free one-on-one call.
