Updated November 2026
The short version
- Landlines run on copper phone lines; VoIP runs over your internet connection.
- VoIP adds features landlines lack, such as calls that ring your mobile, a softphone app and Microsoft Teams compatibility.
- Copper networks are being retired. AT&T plans to exit copper in most of its footprint by the end of 2029.
What is a business landline?
A traditional landline, often called POTS (plain old telephone service), carries calls over copper wires from the phone company's network to your building. Larger offices may use many lines, or a PRI circuit that carries 23 voice channels over copper into an on-site phone system.
Landlines are simple and familiar, and copper lines carry their own power from the phone company. But each line is tied to one location, and adding lines or features usually means new wiring or equipment.
Copper is also being retired. AT&T says it plans to exit its copper network in most of its footprint by the end of 2029 and has already discontinued copper services in more than 500 communities.
What is VoIP?
VoIP (Voice over Internet Protocol) carries your business calls over an internet connection instead of traditional phone lines. Staff can use desk phones, a softphone app on a computer or smartphone, or both. 5x5 business VoIP includes:
- Auto attendant: callers reach the right person or department through a menu.
- Voicemail to email: messages arrive in your inbox.
- Transfer, forwarding and simultaneous ringing: office calls can ring your desk phone and mobile at the same time.
- Softphone app: take calls on your computer or smartphone with the same number and extension.
- Zoom and Microsoft Teams compatibility: use your phone service alongside them, and click any number in Outlook to call.
Key differences at a glance
- How calls travel
- Landline: Copper phone lines
- VoIP: Your internet connection
- Where you take calls
- Landline: At the phone wired to that line
- VoIP: Desk phone, softphone app or mobile, with the same number
- Adding users
- Landline: New lines or wiring
- VoIP: New users added to the service
- Features
- Landline: Basic calling, plus what your phone system supports
- VoIP: Auto attendant, voicemail to email, forwarding, Teams and Zoom compatibility
- Power outages
- Landline: Copper lines carry power from the phone company
- VoIP: Phones and network equipment need power, so plan battery backup
- Future availability
- Landline: Being retired in many areas
- VoIP: Runs on the fiber, fixed wireless and cellular connections replacing copper
Which is right for your business?
A landline may still make sense if
- Your location has no reliable internet connection
- You only need one or two basic lines
- Your phone company still offers copper service where you are
VoIP is likely the better fit if
- Staff work from more than one place
- You want calls to reach mobiles and computers
- You use Microsoft Teams or Zoom
- You are adding users or locations
- Copper service is being retired in your area
Lines for alarm panels, elevators and fax machines are often still on copper. 5x5 replaces aging copper lines like these with modern service that keeps those devices working.
What to check before you switch
- Your internet connection: VoIP call quality depends on it. Dedicated internet access is not shared with other users, for consistent performance at the busiest times of day.
- Your numbers: you can keep your existing business numbers. 5x5 helps you port them.
- Power and backup: plan battery backup for phones and network equipment, and consider a second connection. 5x5 fixed wireless, and 5G and 4G LTE, can provide an additional connection.
- 911 location: FCC rules require 911 calls from VoIP and multi-line phone systems to send a dispatchable location, such as the street address plus floor or suite. Make sure each phone's location is set up correctly.
- Direct 911 dialing: under Kari's Law, multi-line phone systems installed after February 16, 2020 must let users dial 911 without a prefix such as 9, and notify a central point when someone does.
How 5x5 Telecom can help
5x5 Telecom offers business VoIP at a flat, low monthly rate, with enterprise calling features. If you would rather keep the phone system you own, SIP trunking connects it to 5x5's voice service instead. Whether you have a boutique office or a distributed call center with thousands of users, 5x5 has a solution for your business.
Your phones and internet use the same network and are supported by the same team, so call quality problems can be addressed without passing you between vendors. Our 24/7 US-based support team answers every ticket within 60 minutes.