Leased line vs business broadband: an honest comparison

Every provider selling leased lines will tell you that you need one. We sell leased lines, so read the following with that in mind, but we will try to give you the version we'd give a friend: some businesses genuinely don't need one, and we will say who they are at the end.

The difference in one sentence

Business broadband is a shared road, a leased line is your own private lane. Everything else follows from that.

What "shared" actually means for you

With broadband, including modern full-fibre FTTP, the connection from your building back to the network is shared with other homes and businesses around you. Providers call this contention. Most of the time you don't notice. At the moments you do notice, mid-afternoon on a Tuesday when the whole street is on video calls and someone nearby is syncing a few hundred gigabytes to the cloud, your speed sags precisely when you need it most.

Broadband is also asymmetric. That headline "up to 500Mb" figure is the download speed. Upload, the direction your video calls, cloud backups and file sharing actually depend on, is often a fraction of it.

A leased line removes both problems. The bandwidth is dedicated to you, uncontended, so 1Gb means 1Gb at 3pm on the busiest day of the year. And it is symmetric: uploads run as fast as downloads. For a business living in the cloud, which is most businesses now, the upload speed is quietly the number that matters.

The bit people underestimate: what happens when it breaks

Here is the difference that only becomes visible on a bad day. Business broadband comes with a best-efforts fix. Something goes wrong, you report it, and it gets sorted when it gets sorted. A day or two without service is entirely possible and nobody owes you anything beyond apologies.

A leased line comes with a service level agreement, a contractual promise covering uptime and fix times, with money back if it is missed. Ours comes with fix targets measured in hours, not days, and service credits that mean the promise has teeth. Add managed failover, and the SLA becomes 100 percent uptime. In a calibrated building you can go further, with two independent carrier feeds and failover in under 300 milliseconds, quick enough that a video call doesn't drop.

The way to think about it: broadband failures cost you whatever your downtime costs. Leased line failures are the provider's problem, contractually, and they are engineered to be rare in the first place.

The cost difference, honestly

Broadband is cheaper. There is no way to spin this and we won't try. A decent business broadband package might run £40 to £60 a month; our leased lines start at £249 a month for 100Mb. If price is the only axis, broadband wins.

The comparison changes when you cost out downtime. Take a 15-person business with an average loaded cost of, say, £250 per person per day. One full day offline is roughly £3,750 in lost productive time before you count missed calls, unhappy clients and payment systems that couldn't take money. Two such days a year and the leased line has paid for itself, and that is before valuing the everyday difference of calls that don't stutter and uploads that don't crawl.

One cost that people forget to compare: installation. A leased line normally takes 60 to 90 working days to install, often with a wayleave negotiation on top (we've written a separate guide on that particular joy). In our calibrated buildings that whole phase disappears, because the fibre is already in the building. The connection is live the day you move in, at no install cost.

A straightforward way to decide

Choose a leased line if any of these sound like you: downtime visibly costs you money or clients. You run phones, video and core systems in the cloud. You have ten or more people whose work stops when the internet does. You take card payments or run trading, media or file-heavy workflows. You would rather pay a known monthly figure than gamble on best-efforts support.

Broadband is honestly fine if: you are a very small team, mostly doing email, browsing and the odd video call. A day offline would be annoying rather than expensive. Your critical tools would carry on working from a phone hotspot in a pinch.

And a middle path worth knowing about: some businesses run a leased line as the primary connection with cheap broadband as an automatic backup, which gets you resilience without doubling the bill.

Where we land

If your business genuinely fits the broadband profile above, buy broadband and spend the difference on something more useful. If it doesn't, the leased line is not a luxury, it is the boring, load-bearing infrastructure everything else in your business sits on.

If you're not sure which you are, tell us how your team works and we'll give you a straight answer, including "broadband is fine" when it is. Call 020 3026 2626 or get in touch below. And if you're moving into one of our calibrated buildings, the dedicated option is already installed and waiting, which rather changes the maths.

Not sure which you are?

Tell us how your team works. If broadband is fine, we'll say so.