Ask two businesses on the same street what they pay for internet access and you can get answers an order of magnitude apart. Both are buying “fast internet”. They are not buying the same thing.
This guide explains what a leased line actually gives you that business broadband doesn’t, where each one makes sense, and the questions worth asking before you sign a three or five year contract.
The short answer
Business broadband is a shared service. You get a headline speed you’ll often hit, and a fix when something breaks, usually within a few working days.
A leased line is yours alone. The speed is the same up and down, it doesn’t change when the street gets busy, and the contract says how quickly a fault gets fixed.
You’re mostly paying for the promises, not the speed. If a day offline would cost you more than the price difference, that’s your answer.
Fast broadband is nearly everywhere now, which changes the question
The old reason to buy a leased line was that broadband simply wasn’t quick enough. For most UK businesses, that stopped being true a while ago.
So the better question is no longer “which is faster”. Broadband is fast enough for most offices. The question is what happens on the day it stops working, and whether your upload speed is holding you back.
What a leased line actually is
A leased line is a dedicated fibre connection between your building and your provider’s network. Nobody else uses it. That’s the whole idea.
Because it isn’t shared, the speed you buy is the speed you get, at any time of day. It’s also symmetrical, meaning uploads run as fast as downloads. And it comes with a service level agreement, or SLA, which is a written commitment covering how much of the time the line will be working and how quickly a fault will be fixed.
Leased lines can also join sites together directly, without the traffic going out over the public internet.
What business broadband actually is
Business broadband is a shared service. Your connection runs over the same infrastructure as everyone else nearby, and the advertised speed is a best case rather than a promise.
That sounds worse than it is. Full fibre business broadband is genuinely quick, and for an office of ten people sending email, joining video calls and using cloud applications, it’s usually plenty.
The two things you give up are the guarantee and the upload speed. Most broadband uploads far more slowly than it downloads, which matters more than people expect.
The differences that actually matter
The full list of technical differences runs to about twenty. Most of them are the same point restated. These are the ones that change a buying decision.
| Business broadband | Leased line | |
|---|---|---|
| Who else uses it | Shared with other premises nearby | Yours alone |
| Upload speed | Much slower than download | Same as download |
| Speed at 4pm | Can drop when the area is busy | Unchanged |
| Fix times | Best effort, often a few working days | Written into the SLA, often hours |
| Uptime commitment | None in most cases | Typically 99.9% or better |
| Install time | Days to a couple of weeks | Commonly 60 to 90 working days |
| Fixed IP address | Sometimes, often chargeable | Standard, usually a block of them |
| Monthly cost | Tens of pounds | Hundreds of pounds |
| Contract length | 12 to 24 months | Commonly 36 to 60 months |
Where a leased line earns its money
Being offline would actually cost you
Put a number on an hour of downtime. Staff who can’t work, orders you can’t take, calls that don’t land. If a day offline costs more than the yearly price difference, the sums make themselves.
You upload as much as you download
Architects sending drawings, agencies moving video, anyone backing up to the cloud overnight. On broadband, uploads are the bottleneck. A leased line removes it.
You run several sites, or your phones live in the cloud
Joining offices with a private connection keeps that traffic off the public internet. And if your phone system is hosted, call quality depends on a steady connection more than a fast one.
Someone has asked you for an SLA
Some contracts and tenders name an uptime commitment. If yours does, broadband usually can’t meet it on paper, whatever it does in practice.
Where business broadband is the sensible choice
Most small offices don’t need a leased line, and we’d rather say so.
- You’re mainly downloading. Email, web, cloud applications and video calls sit comfortably on full fibre.
- A few hours offline is survivable. Annoying isn’t the same as expensive.
- You need it working next week. A leased line can take three months to install. Broadband can take days.
- The budget is tight. A second broadband line from a different provider often buys more resilience per pound than one leased line.
That last point is worth sitting with. Two connections from two networks, with equipment that switches between them automatically, covers most of what businesses actually fear about being offline.
Questions to ask before you sign
Leased line quotes are hard to compare because providers describe the same thing differently. These questions make them comparable.
- What’s the uptime commitment, and what do I get if you miss it? A percentage with no remedy behind it isn’t worth much.
- What’s the target fix time? Ask for hours, not “priority support”.
- Is the quoted speed the bearer or the bandwidth? A 1Gb bearer with 200Mb of bandwidth is a common quote. It means you can grow later without a new install.
- Are there excess construction charges? If the fibre doesn’t reach your building, someone has to dig. Ask before you sign, not after the survey.
- What’s the install lead time, and what happens meanwhile? Three months is normal. Ask what you’re using in the gap.
- How does the contract end? Check the notice period and what renewal looks like.
What the 2027 switch-off changes
The old copper phone network is being retired on 31 January 2027. Anything still running over it has to move.
For most businesses that’s a phone system question rather than a broadband one. But it’s a good prompt to look at both together, because the answers interact. If your phones are moving to the internet, the connection carrying them matters more than it used to.
If you haven’t started, our guide to the ISDN and PSTN switch-off covers what’s changing and when.
How Chrome does it
We supply both, and we’ll tell you when the cheaper option is the right one.
- A survey before a quote. We check what’s actually available at your postcode, including whether fibre reaches the building, so the price you’re given is the price you pay.
- Plain comparisons. Bearer, bandwidth, uptime commitment and fix times side by side, in language you can take to a board meeting.
- One team afterwards. The same people look after your connectivity, your phone system and your IT support, so nobody gets to blame the other supplier.
You can also check what’s available where you are with our fibre availability checker.
A sensible place to start
Before you compare products, work out two numbers. What an hour offline costs you, and how much you upload on a normal day.
Most businesses have never written either down. Once you have them, the choice between broadband and a leased line usually stops being a debate.
Common questions
Is a leased line worth it for a small business?
Often not, and we’d rather say so before you spend the money. If your team mainly sends email, joins video calls and uses cloud applications, full fibre business broadband usually copes.
The point at which it changes is when being offline starts costing real money, or when you upload as much as you download. Work out what an hour of downtime costs you. If a day offline costs more than the yearly price difference, the sums point one way.
How much does a leased line cost?
Leased lines run to hundreds of pounds a month where business broadband runs to tens. The exact figure depends on your postcode, the speed you buy and how far the nearest fibre is from your building.
The variable that catches people out is excess construction charges. If fibre doesn’t already reach you, someone has to dig, and that cost is passed on. Always ask about it before you sign rather than after the survey.
How long does a leased line take to install?
Commonly 60 to 90 working days, so plan for around three months. It can be longer if a road closure or a landlord’s permission is needed.
Business broadband can be live in days. If you need something working next week, that gap matters more than the speed difference, and it’s worth asking what you’ll use in the meantime.
What internet speed does my business actually need?
Speed matters less than most quotes suggest. A video call uses a few megabits. An office of ten people doing ordinary work rarely troubles a full fibre connection.
Upload speed is the one people underestimate. If you back up to the cloud, send large files or run a hosted phone system, check the upload figure rather than the headline download number.
Can I use two broadband lines instead of a leased line?
Yes, and for a lot of businesses it’s better value. Two connections from two different networks, with equipment that switches between them automatically, covers most of what businesses fear about being offline.
What it doesn’t give you is a written uptime commitment or a guaranteed fix time. If a contract or tender requires one of those, two broadband lines won’t satisfy it on paper.
What is a bearer, and why does it appear on my quote?
The bearer is the size of the physical port your line is delivered on. The bandwidth is how much of it you’ve bought.
So a quote for a 1Gb bearer with 200Mb of bandwidth means the equipment can carry a gigabit, and you’re paying for a fifth of it today. It matters because you can increase the bandwidth later without another install, which is usually a phone call rather than three months of waiting.
Will the 2027 switch-off affect my broadband?
The old copper phone network is being retired on 31 January 2027, and that’s mainly a phone system question rather than a broadband one.
It’s still a sensible prompt to look at both together. If your phones are moving onto the internet, the connection carrying them matters more than it did, and it’s worth checking what you have before the deadline rather than after it.
Related reading
Talk it through with someone
If you’d rather not work through quotes on your own, we can check what’s available at your postcode and put the options side by side. Get in touch and we’ll arrange a chat.
Sources and notes
Full fibre and gigabit availability figures are from Ofcom’s Connected Nations 2025 report, published 19 November 2025, and its Spring 2026 update. Those figures cover residential premises, which is the measure Ofcom publishes; business availability broadly tracks it but is not identical.
Install times, contract lengths and pricing bands are typical UK market ranges rather than quoted figures, and they vary by provider and postcode. The 31 January 2027 date is the industry deadline for retiring the PSTN. We’re describing how these services generally work, not promising a particular speed, price or uptime. Check the wording of any SLA before you rely on it.
