The Short Answer
For 95% of businesses in 2026, VoIP is the right answer. Landlines (POTS) cost more, have fewer features, and carriers are actively retiring them under FCC mandate. The 5% where landlines still win: alarm systems and elevators that require UL-certified analog connections (even here, cellular replacements exist), rural locations without reliable internet, and life-safety applications where analog failover is required by code.
If you're asking this question for a general business phone system, VoIP wins. The rest of this article explains why and helps you pick the right VoIP approach.
Cost Comparison: The Numbers Are Clear
Traditional POTS lines cost $35–65 per line per month with no features beyond basic calling. In a 50-person office, a typical small business might have 15–20 lines:
- 15 POTS lines: $525–975/month
- 20 POTS lines: $700–1,300/month
- Plus: Additional costs for long distance (often metered), call waiting, call forwarding—features that come free with VoIP
VoIP Option 1: SIP Trunking (Carrier-Grade)
SIP trunking runs $15–25 per channel per month. A channel handles one call simultaneously. Most businesses need 1 channel per 4–6 employees. For a 50-person office:
- 8–12 channels needed
- Monthly cost: $120–300
- You bring your own PBX (on-premises or cloud-based)
- Requires technical expertise to manage
VoIP Option 2: Unified Communications as a Service (UCaaS)
Full cloud phone system costs $20–35 per user per month and includes:
- Video calling, team messaging, auto-attendant
- Mobile app (use your cell as your business line)
- Call recording, voicemail-to-email, call analytics
- No PBX hardware to buy or manage
- For 50 users: $1,000–1,750/month
Savings comparison: A 50-person office saves $3,000–10,000 per year by switching from POTS to UCaaS, and gains a modern feature set.
Feature Comparison: The Gap Is Enormous
| Feature | POTS Landline | SIP Trunking | UCaaS (Cloud) |
|---|---|---|---|
| Basic calling | Yes | Yes | Yes |
| Voicemail | Basic | Full featured | Voicemail-to-email |
| Auto-attendant / IVR | No | Yes | Yes |
| Ring groups / hunt groups | No | Yes | Yes |
| Call recording | No | Yes | Yes |
| Mobile app (use cell as business line) | No | With PBX app | Native |
| Video calling | No | With PBX | Yes |
| Team messaging | No | No | Yes |
| Call analytics | No | Limited | Full dashboard |
| Data capacity | Voice only | Voice only | Multi-protocol |
The feature gap alone justifies the switch for most businesses. POTS lines are single-purpose voice—they cannot carry data.
Reliability: Uptime and Failover
Traditional landlines are "always on" because they draw power from the phone company's network, not your building. VoIP requires internet connectivity and power at your location. If your internet goes down, VoIP goes down.
Mitigation Strategies
- LTE failover router ($50–150/month): Automatically switches calls to cellular LTE if broadband fails. Seamless to users.
- Battery backup on routers and phones ($200–500 one-time): Keeps VoIP running for 4–8 hours during power loss.
- Mobile app failover: Configure your VoIP system to route calls to your cell phone (via the mobile app) if internet is down.
Bottom line: Modern VoIP with proper failover equals or exceeds POTS reliability for business use. You gain flexibility (you can take calls anywhere) while maintaining uptime.
Call Quality: Expectations and Reality
POTS is consistent but limited (voice only, no HD audio). VoIP call quality depends entirely on your internet connection.
On a Good Connection
On stable broadband with 20+ Mbps and low jitter, VoIP HD audio is objectively better than POTS. You get crystal-clear voice, silence suppression, and codec choice.
On a Poor Connection
On a congested, high-latency, or unstable connection, VoIP sounds worse: dropped syllables, delays, occasional robotic artifacts.
The Solution: Quality of Service (QoS)
Enable QoS settings on your router to prioritize voice traffic over casual browsing and streaming. Most businesses with decent broadband notice no quality difference; many notice an improvement. QoS ensures VoIP packets move to the front of the line.
When Landlines Still Win (2026 Edition)
There are specific cases where analog POTS or analog-equivalent solutions still make sense:
Elevator Emergency Phones
Building codes often specify analog emergency phones. Check your local requirements. Some jurisdictions now accept cellular or hybrid solutions, but many still require hard-wired analog. Consult your building manager.
Fire Alarm and Security Panels
Many require analog connection for central monitoring to meet insurance and fire code requirements. Cellular-based alarm systems are becoming standard and widely accepted, but check with your alarm company and local authority. Upgrading to a cellular system is often cheaper than maintaining POTS lines.
Fax Machines
VoIP fax (FoIP) works but is imperfect. T.38 protocol exists and handles modern faxing, but not all VoIP providers support it reliably. If you still rely heavily on faxing, you may need to keep one POTS line or switch to a dedicated fax service (cloud-based faxing via email is increasingly popular).
Rural Sites Without Broadband
In the few remaining areas without reliable broadband, POTS may be your only voice option (for now). However, satellite internet and fixed wireless are expanding rapidly. Check with your provider on future alternatives.
Life-Safety Applications
Applications that require analog failover by code (e.g., critical medical facilities) may need to retain POTS as a hard requirement. Consult your compliance officer.
For everything else, VoIP is the answer.
Frequently Asked Questions
Can I keep my existing phone numbers when switching to VoIP?
Yes. Number portability (LNP) is legally protected in the United States. You can port your existing phone numbers to a VoIP provider within 24–48 hours. Work with your new VoIP provider to initiate the port; they'll handle coordination with your current carrier. The process is straightforward and usually free.
What internet speed do I need for VoIP calls?
A single VoIP call uses about 0.6 Mbps upload and 0.6 Mbps download. For a 50-person office with 10 concurrent calls, budget 6–8 Mbps dedicated. However, we recommend 20+ Mbps broadband with QoS enabled to handle VoIP alongside normal business data traffic (email, cloud apps, web browsing) without quality degradation.
Will my alarm system work on VoIP?
Standard alarm systems designed for analog POTS will not reliably work on standard VoIP. Alarm monitoring requires UL-certified connections. Your options: (1) Upgrade to a cellular alarm system, (2) Keep one POTS line for the alarm only, (3) Use a UL-certified analog gateway designed for alarms (a hardware device that bridges VoIP to analog for the alarm). Consult your alarm company before switching.
Does VoIP work during a power outage?
No. VoIP requires both internet connectivity and power (both your router and phones need electricity). POTS, by contrast, is powered by the phone company and works during outages. Mitigation: Use battery backup on your router and VoIP phones, configure mobile app failover, or deploy an LTE failover router as a backup connection.
What happens to my POTS lines after the FCC deadline?
The FCC has directed all carriers to retire traditional TDM circuit-switched networks by 2025, with extensions to 2027 for certain areas. After the deadline, POTS will no longer be available for order or support. Major carriers are actively retiring lines and pushing customers to VoIP or alternatives. Plan your transition now if you have not already.
Let ITG Transition Your Voice Infrastructure
Ready to move from POTS to VoIP? We'll assess your broadband, configure failover, and handle the migration—no disruption.
Schedule a Consultation