AT&T Just Discontinued Your POTS Line. What Now?

If you got a letter from AT&T or your local CLEC this year saying your “Plain Old Telephone Service” line is being discontinued, you are not alone. The FCC granted the major carriers permission to retire copper years ago, and the rolling shutoff is now reaching West Texas in earnest. By 2027, copper telephone service will be effectively gone in Lubbock for new installations and gradually retired for existing ones.

This post is for the business owner staring at the letter wondering what to do about the alarm panel, the fax machine, the elevator phone, the fire alarm, and the credit card terminal that all use POTS lines. The honest, vendor-neutral answer.

What POTS actually does that VoIP often doesn’t

POTS lines have three properties that have made them the default for life-safety and infrastructure devices:

1. They work without commercial power. The line itself carries DC voltage from the central office. Your phone works during a power outage as long as the wires are intact.
2. They are dedicated, not shared. A single device on the line gets the full bandwidth, which is laughable by modern standards but still reliable for analog signaling.
3. They support analog devices natively. Faxes, alarm panels, elevator emergency phones, fire alarm communicators — all built around POTS specifications.

Replacing a POTS line means replacing those three properties, not just routing a different protocol over different wire.

The four real replacements

There are four legitimate replacement paths, in roughly increasing order of cost and reliability:

1. POTS-in-a-box (cellular gateway)

A device the size of a paperback book that has a cellular modem on one side and an RJ-11 jack on the other. Your existing analog device plugs in and thinks it’s still on a copper line. The device translates dial tones, ring signals, and DTMF tones to a SIP-over-cellular path.

• Cost: $40-70/month per line, plus $200-400 device.
• Best for: alarm panels, fax machines, the credit card terminal at a small retail counter.
• Watch for: verify the gateway is on a battery backup (most have built-in 8-hour batteries; verify yours does). Cellular reliability varies by location — test the actual signal at the install point before buying.

2. SIP trunk to your VoIP system

If you already have a modern VoIP phone system (3CX, Issabel, RingCentral, Zoom Phone, the Microsoft Teams calling plan), the system can usually accept a SIP trunk from a carrier and present analog ports for your legacy devices through an ATA (analog telephone adapter).

• Cost: $15-30/month per line via SIP, plus $100-200 ATA per analog endpoint, plus your existing VoIP system cost.
• Best for: offices that already have a VoIP system and just need to absorb a few legacy lines.
• Watch for: if your VoIP system runs on internet and your internet goes down, your “POTS replacement” goes down too. Cellular failover on the gateway, or a cellular-backed UPS for the whole stack, becomes mandatory.

3. Dedicated cellular line per device

For devices where reliability is non-negotiable — fire alarm communicators, elevator phones in commercial buildings — code often requires a dedicated cellular communicator that reports independently of the main building network. Specialized vendors (DMP, Honeywell, Bosch) sell these for the alarm market.

• Cost: $15-40/month per device, plus $300-800 device.
• Best for: fire panels, elevator phones, security panels under monitoring contract.
• Watch for: local code may specify dual-path (cellular + IP). Confirm with your fire marshal and your alarm company before buying.

4. Hosted VoIP with full migration

If you have multiple POTS lines plus a desk phone fleet, the move that usually makes sense is a complete migration to hosted VoIP, with the legacy devices either replaced (modern fax-to-email, modern alarm panel) or attached via ATA.

• Cost: $25-85 per extension/month depending on tier. Replaces the POTS lines AND the desk phones AND the call routing.
• Best for: offices doing more than incremental replacement; this is where most of our customers land.
• Watch for: number porting can take 30-90 days. Plan the cutover. Don’t let the carrier disconnect copper before the new numbers are live.

The order of operations we use

For a customer with 4-8 POTS lines getting the discontinuation letter:

1. Inventory. Walk every line and document: what device is on it, what is the device for, what’s the call volume, is it life-safety, is it required by code?
2. Triage. Sort into “fax/credit card” (cellular gateway), “alarm/elevator/fire” (dedicated cellular communicator), “voice business lines” (move to VoIP).
3. Order replacements with overlap. Keep the copper alive through the transition. Test each replacement under real conditions before disconnecting the old line.
4. Document the cutover. Number porting dates, account closures, billing transitions.
5. Update your monitoring contracts. Alarm and fire companies need to be told about the new path; some require certification of the new device before signing off.

Common mistakes that cost real money

• Disconnecting copper before testing the replacement under power loss. Hard lesson learned by businesses whose alarm panel goes silent during the first storm.
• Assuming the cellular gateway has a battery. Some don’t. Always confirm with the manufacturer spec sheet, not the salesperson.
• Skipping the fire marshal conversation. Fire alarm communication paths are inspected and certified. Your fire panel vendor needs to confirm the new path is code-compliant.
• Letting the porting deadline slip. Numbers in port-pending status can be lost if the source carrier disconnects too early.

What we do for customers facing this

If you’re on a Steel or higher Managed plan, POTS replacement falls under the network/voice scope and we run it as a project. Hourly customers can have us do a one-time POTS audit + cutover for a flat fee — typical project is 8-16 hours of engineering depending on line count.

Phones page has the rates for VoIP if a full migration is the right play. Free IT Blueprint Assessment covers POTS audit as part of a broader walk if you want one set of eyes on the whole environment.