The Real VoIP vs. Landline Cost Comparison for Business

Most businesses assume VoIP is cheaper than a traditional landline. In almost every case, that assumption is correct, but the actual numbers vary significantly depending on what kind of landline setup you’re replacing, how many lines you’re running, and how heavily your team uses the phone. “Cheaper” can mean $200 a month in savings or $2,000 a month. The gap is wide enough that it’s worth understanding the real cost structure before you make a decision.

This comparison breaks down what each option actually costs, not just the monthly bill, but the full picture including setup, hardware, maintenance, and the charges that quietly add up over time.

First: What Are You Actually Comparing?

“Landline” means different things depending on when and how your phone system was set up. Before running the numbers, it helps to know which category you’re in.

Analog POTS lines (Plain Old Telephone Service) are traditional copper-wire phone lines from a local telephone company, billed per line per month. They’re common in small offices and are increasingly expensive because carriers are actively retiring this infrastructure.

PRI circuits (Primary Rate Interface) are the enterprise version, a single digital circuit that carries up to 23 simultaneous calls, typically paired with an on-premise PBX. Common in businesses with 10 or more lines. Higher upfront cost but lower per-call cost than analog.

Cloud VoIP (also called UCaaS or hosted PBX) routes calls over your internet connection to a cloud platform. You pay per seat per month. No local PBX hardware to maintain. This is what most businesses switching from landlines move to.

SIP trunking is a hybrid: your calls travel over the internet via SIP, but they terminate on an on-premise PBX you own and manage. Lower monthly costs than cloud VoIP, but you carry the hardware and maintenance burden.

The most common comparison for businesses evaluating a switch is analog POTS or PRI versus cloud VoIP, so that’s the focus here.

Side-by-Side Cost Comparison

Cost Category	Traditional Landline	Cloud VoIP
Setup and installation	$500–$3,000+ (wiring, hardware, carrier provisioning)	$0–$500 (phones only; no wiring or carrier installs)
Monthly cost per line/seat	$40–$80/line (analog); $800–$2,500/month (PRI circuit)	$19.95–$45/seat/month (typically includes most features)
Local calls	Included	Included
Domestic long distance	$0.03–$0.10/min, or bundled at higher base rate	Included in most plans
International calls	$0.10–$1.50+/min depending on country	Often far lower, but subject to charge
Phone hardware	$150–$400/phone + PBX system ($5,000–$50,000+)	$80–$300/IP phone (or $0 with softphone app). Many providers can roll phone costs into monthly fee meaning nothing out of pocket
Moves, adds, and changes	$75–$250/change (often requires site visit)	Self-service via admin portal; no charge. Many providers include remote service with the monthly fee.
Maintenance and support	$1,500–$8,000/year (PBX maintenance contract) or billed as T&M per event	Included in subscription
Feature upgrades	Often require hardware or firmware upgrades	Pushed automatically by provider
Scalability cost	New line = new circuit order (days to weeks, fees apply)	Add a seat in minutes; provisioned remotely

What a 20-Seat Business Actually Pays

Abstract numbers are harder to act on than a concrete example. Here’s what the cost structure looks like for a typical 20-person office:

Traditional landline (analog, 20 lines): 20 analog lines × $55/month = $1,100/month in line charges. Add a leased or maintained PBX: $250–$400/month in maintenance fees. Long-distance charges on a typical office run $100–$300/month. Occasional technician visits for moves and changes: $500–$1,500/year. Estimated monthly total: $1,500–$1,900/month.

Cloud VoIP (20 seats): 20 seats × $30/month = $600/month, with unlimited domestic calling, all standard features (voicemail, auto-attendant, call recording, conferencing), and no hardware maintenance. International calling costs depend on volume but are typically 80–90% less than landline rates. Estimated monthly total: $600–$750/month.

That’s a difference of roughly $900–$1,200 per month, or $10,000–$14,000 per year, for a 20-person office, not counting the PBX hardware replacement cycle, which eventually hits every business still running an on-premise system.

The Hidden Costs of Traditional Landlines

The monthly line charge is only part of what businesses pay for landline service. Several costs tend to be invisible until they show up on a bill or require a capital expenditure:

Carrier rate increases. Local and long-distance rates for legacy POTS lines have climbed steadily as carriers invest less in copper infrastructure and focus on retiring it. Businesses on analog lines have seen 5–15% annual increases in many markets.
PBX hardware refresh. On-premise PBX systems have a lifespan. When the hardware reaches end-of-life, replacement costs $10,000 to $50,000 or more depending on system size, a lump sum that doesn’t show up in monthly operating costs until it arrives.
Idle capacity. Businesses that ordered lines for peak capacity pay for those circuits every month whether calls are being made or not. A PRI provisioned for 23 channels runs the same monthly cost at 10% utilization as it does at 90%.
Feature limitations. Adding features like call recording, auto-attendant updates, or mobile integration to a legacy PBX often requires paid software licenses or hardware modules, costs that VoIP platforms bundle into the base subscription.

The Real Costs of VoIP (Being Honest About What’s Required)

VoIP’s lower cost profile is real, but it comes with network requirements that landlines don’t have. These aren’t dealbreakers for most businesses, but they should be factored into any honest comparison.

Internet bandwidth. A reliable VoIP call requires roughly 100 Kbps per concurrent call. A 20-person office with 10 simultaneous calls needs about 1 Mbps dedicated to voice, which is modest by modern broadband standards, but it needs to be reliable. VoIP over a congested or inconsistent connection produces choppy audio and dropped calls.
QoS configuration. For the best call quality, your router and network switches should be configured with Quality of Service (QoS) settings that prioritize voice traffic over data. This is a one-time setup task, not ongoing overhead, but it requires someone who knows what they’re doing.
Internet redundancy. If your internet goes down, so does your VoIP phone system. Businesses that need continuous phone availability during outages typically add a 4G/LTE failover connection. The cost is usually $40–$80/month for a backup circuit that’s rarely used. But with available mobile apps and a reliable cell phone service, this may not be required for the voice calls. Simply log into your app and you are back in business if the internet goes down.

Cabling matters either way. Whether you’re running VoIP phones or traditional desk phones, your in-wall cabling infrastructure affects call quality and reliability. If your office is running old Cat5 wiring or has undocumented runs, it’s worth assessing that before any phone system change. Mastor installs and certifies voice and data cabling alongside phone system projects, so your infrastructure is ready for whatever you’re running on it.

Long-Distance and International Calls

For businesses that make frequent long-distance or international calls, VoIP’s per-minute rates can produce some of the most dramatic savings. The FCC’s guidance on international calling costs notes the enormous range in carrier pricing, rates that VoIP providers, who route calls via SIP over the internet rather than through the traditional telephone network, consistently undercut.

Some examples of where this shows up:

A law firm making regular calls to Mexico or Canada might pay $0.05–$0.15/min on a traditional plan versus effectively $0 on a VoIP plan with included North American calling.
A company with offshore vendors calling India, Southeast Asia, or Eastern Europe routinely saves 70–90% on those call costs by switching to VoIP.
Conference calls billed per-participant-minute on a traditional conferencing service are replaced by video meetings available in most of the standard service plans of most cloud phone platforms.

When Traditional Lines Still Make Financial Sense

There are situations where staying on a landline, or keeping a handful of analog lines, is the right financial call.

Alarm systems and elevator lines. Many monitored alarm systems, elevator emergency phones, and credit card terminals require a dedicated analog line. These can often be handled with an ATA (analog telephone adapter) that connects to your VoIP system, but some older systems require a genuine POTS line. In those cases, keeping one or two analog lines for specific devices while moving everything else to VoIP is a reasonable hybrid.
Very low call volume. If a business makes fewer than a few hundred minutes of calls per month, the per-seat cost of a full VoIP subscription may exceed what a single analog line would cost. Small offices with truly minimal phone needs sometimes find a basic landline is the simpler choice.
Internet unreliability with no backup option. Businesses in locations with limited broadband options and no practical way to add redundancy have a legitimate reason to keep traditional service. This applies to a small number of businesses in specific rural areas; it’s not a common constraint for most commercial locations.

On-Premise VoIP vs. Cloud VoIP: A Cost Note

If you like the call cost savings of VoIP but want more control over your phone system, an on-premise IP PBX paired with SIP trunking can deliver lower monthly costs than cloud VoIP, particularly for larger organizations where per-seat pricing adds up. The tradeoff is that you own the hardware and bear the maintenance responsibility. For businesses with existing IT infrastructure and in-house support, that tradeoff often makes sense. For businesses that want simplicity, cloud PBX wins on total cost of ownership because the maintenance overhead disappears.

The right answer depends on your seat count, call volume, IT resources, and how long you plan to stay in your current space. There’s no universal winner, but for most small and mid-size businesses, cloud VoIP delivers a lower total cost with less operational friction than any landline alternative.

Get a Real Number for Your Business

The most accurate comparison isn’t a published table. It’s your current phone bill next to a quote for a system sized to your actual needs. At Mastor, we’ll look at what you’re running now, what it’s actually costing you, and what a properly configured VoIP or cloud phone system would run for a business your size.

We’re not going to oversell seats you don’t need or quote you a system built for someone twice your size. Contact us or call (314) 997-9007 and we’ll give you a straight answer.