What is a leased line? Definition, benefits and costs explained

Most businesses start out with broadband.

It’s great for browsing, file backups, video calling, communicating with customers, and keeping cloud applications, point of sale and various devices connected.

For some businesses, that’s all they’ll ever need, and we’d certainly never recommend a leased line to an organisation that gets everything they need from business broadband.

But as businesses grow, things can change. More staff, more cloud applications, larger file transfers, and an increasing need for the connection to always be available can all change the picture.

At that point, leased lines enter the conversation. They’re dedicated internet connections designed for organisations that need consistently high performance, reliability and availability.

In this article, we’ll cover the whats, whys and hows of leased lines, we’ll compare leased lines to business broadband, and we’ll help you work your way through answering the all-important question: “does my business need a leased line?”

What is a leased line?

This is probably the best place to start. After all, asking “what is a leased line” is probably what made you click on this article.

A leased line is a dedicated internet connection, reserved exclusively for one business. In contrast to regular business broadband, that means it isn’t shared with other users.

And when we say “shared”, we don’t mean that other homes and businesses are literally using your connection. What you’re sharing is the underlying network and available bandwidth on that network. While no one else is using your actual connection, the full capacity of that network isn’t always available to your business.

Because a leased line connection gives you dedicated internet access, you get predictable performance and guaranteed speeds. And that’s the leased line definition at its simplest.

So what about the term we just used? What is dedicated internet access? Dedicated internet access (DIA) is a term that you’ll often see used interchangeably with leased lines. It helps to communicate the fact that this is a private internet connection, available exclusively to your business.

That dedicated internet connection is the definition of a leased line in a nutshell.

What does “leased line” mean?

While it’s easy to find explanations of what leased lines do, or how they help, most guides ignore the actual leased line meaning.

So here’s the quick explainer.

A leased line is called a leased line because the connection is leased exclusively to a single customer. The term dates back to the days when businesses would lease private telecommunications circuits rather than use the public telephone network.

That’s in contrast to the “shared” lines that broadband connections use. So with a leased line, you know you’re getting dedicated bandwidth, because the literal meaning of the term says so.

And that’s where the differences to business broadband really start to show. Because fundamentally, it’s about who has access to the line – multiple homes and businesses, or just you.

How does a leased line work?

The first thing to remember when it comes to a leased line is that it’s a dedicated fibre connection to your property. You might hear the phrase “uncontended connection” when you’re researching leased lines. That simply means that a leased line gives you a direct connection to your provider’s network that isn’t shared with any other users, unlike the shared connection used by regular broadband.

A leased line also gives you symmetrical speeds which means your upload and download speeds are the same.

Traditional broadband tends to prioritise download speeds, which makes sense. For homes especially, streaming video, downloading files, and even browsing the web all make much more use of the connection’s download speed.

But for businesses, uploads can be just as – if not more – important. Consider:

• Cloud applications
• Video conferencing
• VoIP
• Large file transfers
• Multi-site organisations

These are all situations where a faster upload speed is better.

Leased lines also come with something broadband services often can’t match - service guarantees. When you need your internet connection to be available no matter what, the service level agreements (SLAs) that leased lines come with tend to guarantee high levels of uptime (think 99.9% as standard).

That’s performance, consistency and availability. Three factors that are massive for many businesses.

Leased line vs business broadband: what you’re actually getting

Now you know the basics, you might find yourself asking “why would I pay more than broadband?”

The answer to that question really comes down to your requirements, and the understanding that broadband and leased lines are designed for different business needs.

That doesn’t automatically make one better than the other. But if you’re unsure about a leased line vs broadband, it’s worth taking a quick look at the differences across a few key features.

What’s the difference between a leased line and broadband?

Feature	Business broadband	Leased line
Shared connection	Yes	No
Upload speeds	Usually slower	Symmetrical
Contention	Shared	Uncontended
Speed guarantees	Limited	Guaranteed
SLA	Limited	Included
Reliability	High	Enterprise-grade

Perhaps the biggest difference between the two products is the consistency you get with a leased line. Although the performance of business broadband – especially full fibre – can be excellent, broadband can also fluctuate. Imagine a busy part of the day when every business in your area is using their broadband heavily, and you need to backup an important file. In that scenario, you may find your upload to be slower than you’d like. You might find video calls buffering or cloud applications stuttering.

With a leased line, the performance available to your business remains consistent regardless of how busy the wider network is.

And it’s not just guaranteed speeds. Leased lines are designed to give you the predictability and dependability your business needs. Which is highly valuable if your business depends on its connection being available continually.

At Zen, we find that businesses often start to consider leased lines when connectivity becomes business-critical. When downtime starts to affect customers, revenue or productivity, that’s usually the indicator that a step up to a leased line might start to produce positive business benefits.

Why do businesses choose leased lines?

Or, perhaps, why would a business choose a leased line instead of broadband?

First of all, every business is different, and every business has a different threshold at which one makes more sense than the other. But generally speaking, there are five main benefits of a leased line for businesses.

Benefit 1: Reliable business internet

That means fewer interruptions, more predictable performance, and an ability to cope much more reliably with peak-time demand.

It also means less time spent troubleshooting connectivity issues and more time focused on running your business.

Benefit 2: Cloud applications

Business internet use is increasingly cloud-based. Leased lines offer better experience with SaaS applications, improved access to cloud platforms, faster and more reliable cloud backups, and enhanced remote access.

When cloud applications are vital to your day-to-day, leased lines provide a platform for smoother, more reliable access.

Benefit 3: Video conferencing and collaboration

Think Teams, Zoom, Google Meet, VoIP, and a host of other communication and collaboration platforms.

Think collaboration between teams, sites, suppliers and partners.

In other words, all the ways that modern businesses do business. Most meetings today don’t take place in person, most file sharing is done collaboratively over cloud-based platforms, and with the PSTN shutdown looming, most calling is 100% cloud-based too.

Leased lines provide the most reliable, consistent, high-performance platform for modern business communication and collaboration, including powerful CloudComms.

Benefit 4: Large file transfers

Thanks to symmetrical speeds, with a leased line your uploads are just as fast as your downloads. For general browsing that might make little difference, but when it comes to regular large file transfers or cloud backups, the difference can be enormous, saving you time and stress, and giving you the tools to get the job done your way.

Benefit 5: Business growth

Business broadband is great for smaller businesses or those with limited needs. But what happens when your team grows, when more of your workload moves online, when you need a reliable platform for modern voice and video communications?

That’s when you really start to see the leased line benefits.

As your business grows, leased lines give you the scalability you need. Modern businesses need modern business connectivity – and that’s where leased lines really start to show their value.

What are the advantages and disadvantages of a leased line?

Every technology decision involves trade-offs. A leased line will generally offer higher levels of performance, reliability and consistency than business broadband, but that doesn’t mean it’s always the right decision for every business.

That’s why when you’re making your decision, it’s important to weigh up the leased line advantages and disadvantages.

Leased line advantages:

• Dedicated bandwidth
• Guaranteed speeds
• Symmetrical performance
• SLA-backed support
• Improved reliability

Leased line disadvantages:

• Higher monthly cost
• Longer installation times
• Not every business needs one

Whether a leased line or a standard business broadband connection is the right choice depends on how critical connectivity is to your business. If you need guaranteed performance and guaranteed uptime, a leased line is the right choice.

If high performance full fibre broadband gives you everything you need, a leased line may not be worth the additional cost and complexity.

Is a leased line right for your business?

Before we get into this section, we need to repeat an important point. Not every business needs a leased line.

This isn’t about “this is the best connection so you need it”. Many businesses are perfectly served by broadband, and if you don’t need a business leased line you probably won’t even notice the benefits.

So who needs a leased line? If you’re asking do I need a leased line, consider some of the situations in the following table. If any of these are familiar to your business, then it’s time to start giving it some consideration.

Situation	Consider a leased line?
Slow uploads	Yes
Cloud-first business	Yes
Frequent video calls	Yes
Large data transfers	Yes
Small team	Maybe not
Connection not business-critical	Perhaps not
Basic browsing and email	No

When does the cost justify the upgrade?

The question of is a leased line worth it often comes down to the cost of downtime.

Zen research says that businesses lose 11 hours of productivity every week due to WiFi issues. That’s just one implication of poor connectivity.

When the internet goes down – even occasionally – or when performance isn’t quite what you’d like it to be, you can experience delays, lost productivity, staff frustrations, customer problems, even lost sales.

It all adds up. And if connectivity is crucial to your business, downtime – any downtime – can be hugely problematic. It affects customer experience and can even have compliance implications.

At that point the ROI on an investment in leased lines might come as much, maybe even more, from avoiding problems than increasing speed.

Speed is usually the headline when it comes to business connectivity, but resilience, reliability, availability and consistency are all arguably more important.

You’ll probably already know the extent to which your business can tolerate drops in performance and lost connectivity. The question is, is your current business broadband connection giving you what you need?

How much does a leased line cost?

So that’s why you might consider the extra cost. But we haven’t discussed the actual price yet.

As with most business technology investments, there isn’t a single answer. The actual pounds and pence cost of a leased line can depend on multiple factors.

What affects leased line cost?

When you’re considering a leased line, it’s worth contacting your provider for a quote that’s based on your requirements. After all, the cost of a leased line can be influenced by factors including:

• Location
• Distance from the network
• Required bandwidth
• Resilience requirements
• Managed services

But it’s probably worth knowing that what you’ll pay for a leased line depends very much on your business needs. A 10 Gbps fully managed service is going to be more expensive than a 1 Gbps fixed line. That’s why it’s important to work out what your business needs and choose the right service for you.

But if you’re worried about price, you might be surprised to learn that a leased line with Zen can be had from as little as £48 pm (ex. VAT).

Different services for different budgets

In other words, leased lines aren’t only for large enterprises. That’s one of the main myths that surround Ethernet leased lines: small businesses need broadband; larger businesses need a fibre leased line.

The truth is there are a range of services for a range of business needs. 

For example, Zen offers services ranging from Ethernet Light that provides a cost-effective combination of broadband and leased lines over an Ethernet over FTTP (EoFTTP) circuit to Ethernet 1000, Ethernet 10000, and even Enterprise Managed services.

That’s a range of services across different speed tiers and different service levels, designed for very different business needs. Whether you need just a little more than business broadband offers, or a full managed enterprise-grade solution, or something in between, there’s a leased line service for you.

So when you’re looking at price, it’s important to identify what you need first of all. We can help you do that of course, just contact us here.

Installation: what to expect

The most important thing to remember about leased line installation is that it typically takes longer than a business broadband install.

Often, you’re having a dedicated line installed, and depending on the requirements, that can often take a little time.

Survey and feasibility assessment

This involves a site survey, route planning and an infrastructure review.

Because leased lines are often built specifically for the customer, they may be available in locations where standard full fibre services aren’t yet available. But that’s generally because you’re ordering a bespoke installation. And there can obviously be cost and time considerations associated with that.

Typical installation times

Because of that, a typical leased line installation might take around 60-90 days.

If complex work is required, or the installation is crossing private land for example, the install could take longer.

None of that is a reason to not choose a leased line of course, but if you’re asking “how long does a leased line installation take”, and you need an internet connection quickly, broadband is generally a much safer option. One thing to bear in mind is that it’s often possible to have a temporary broadband circuit fitted while you wait for your leased line installation to complete.

Minimising disruption

While you’re waiting for the install, it can be comforting to know that most of the work involved in the installation takes place externally.

Engineers may need access to the outside of your premises at times throughout the process, but there should be limited impact on day-to-day business operations. Once the line exists, connecting it to your business should be a fairly seamless process.

Choosing a leased line provider

Not all leased line providers are the same.

Most will offer high-speed connectivity. The difference is often in the service that sits behind it.

When comparing providers, look closely at:

• Uptime commitments
• Service level agreements
• Fault response times
• Technical support
• Network reach and resilience

These are often the factors that determine how well a provider performs when your business needs them most.

With Zen you get:

• The UK's largest 10 Gb Ethernet footprint
• UK-based NOC
• Cisco and Fortinet options
• 99.9% uptime SLA
• 100% resilience option
• Which? Recommended provider
• B Corp certification
• Independent and people-first

So what should you look for in a leased line provider? You need a provider that can give you the speed, reliability and performance you need, backed by a people-first, planet-first outlook that prioritises your experience and your success. We might be biased, but we think you’ll find that provider in Zen.

Frequently asked questions

How long does leased line installation take?

We’ll try to get your leased line installed as quickly and smoothly as possible. You can typically expect installation to take between 60-90 days.

EoFTTP installations can usually take place much more quickly.

What speed leased line do I need?

This all depends on the type of business you are, and what you need to do with your internet connection. Are you a small business? A growing business? An enterprise?

Are you supporting a small team, or a large office?

Are you connecting multiple sites or simply looking for a reliable connection?

Are you regularly backing up large files, conducting video conferencing, live streaming, or just connecting devices that use little bandwidth.

We offer speeds from 100 Mbps to 10 Gbps, helping ensure there’s a solution for almost every business requirement.

Can I get a leased line at any location?

Leased lines are generally available in many locations. In fact, because the line is often custom installed, you may be able to get a leased line in locations where full fibre isn’t yet available.

In some instances, a survey may be required to determine availability.

But please speak to us for an accurate picture of availability where you are.

Do I really need a leased line for a small office?

This really depends on what you need from your connection.

When the availability of your connection is non-negotiable, the answer may be yes. But often, you will be fine with a business broadband connection.

If you need additional assurances of reliability, you can add 4G backup to a Zen business broadband connection, instead of incurring the additional expense of a leased line.

Is a leased line the same as fibre broadband?

No, a leased line is not the same as fibre broadband.

A leased line is a dedicated, private, uncontended connection that is exclusive to your business. It offers guaranteed speeds, performance and availability.

Full fibre broadband operates on a shared public network, which means that speed can fluctuate depending on how busy that network is at any given time. But with a leased line, you have access to the full bandwidth you’ve purchased at all times.

That being said, Ethernet over FTTP options such as Zen Ethernet Light are available that bridge the gap between full fibre broadband and leased lines, offering many of the benefits of a leased line at a price and convenience point much closer to fibre broadband.

What is dedicated internet access (DIA)?

Dedicated internet access is a private internet connection built for businesses. Unlike standard broadband, the line is uncontended, which means your bandwidth is not shared with any other users. DIA connections provide guaranteed bandwidth, symmetrical upload and download speeds and service level agreements (SLAs) that ensure high levels of availability and fast repair times.

Do leased lines guarantee speeds?

Yes. When you purchase a leased line, you’re guaranteed the bandwidth you pay for. Whether that’s 100 Mbps or 10 Gbps, because the connection is yours and yours alone, you’re not sharing your bandwidth with any other users, which means no slowdown during busy periods, just guaranteed performance day in, day out.

Ask our experts if a leased line is right for your business

For businesses that depend on their internet connection, leased lines offer guaranteed speeds, availability and performance.

They allow file uploads, file sharing, video calling, accessing cloud applications, voice comms and more to happen smoothly and reliably.

There are also a range of leased line speeds available to suit a wide range of businesses and business needs.

But every business is different, and not every business needs a leased line.

If you’re assessing your business internet needs, we can help you think about your requirements and recommend the appropriate solution.

Read more about leased lines from Zen here and use the form on the page to contact us. We’re happy to help.