Leased Line vs Full Fibre: Which Does a Business Need?

Last checked: 5 October 2026

Most small UK businesses are well served by full fibre (FTTP) broadband. A leased line is worth paying for when your business cannot tolerate a slow repair, needs fast uploads as well as downloads, or needs bandwidth that is never shared with anyone else. The core difference is simple: full fibre is a shared connection with a best-efforts service, while a leased line is a dedicated, symmetrical fibre circuit to your premises with a business-grade repair commitment.

This guide compares the two using Openreach's own product information, explains when each makes sense, and gives a worked example you can adapt to your own office.

What is the difference between a leased line and full fibre?

Both run on fibre optic cable. The difference is who else shares the fibre and what the provider promises if it fails.

Full fibre (FTTP) connects the exchange to your building entirely over fibre. Openreach describes it as a "shared fibre connection with your local area". Its business full fibre offers download speeds of up to 1Gbps and upload speeds of up to 220Mbps, so upload is a fraction of download.

A leased line (Openreach sells the underlying product to providers as Ethernet, including Ethernet Access Direct or EAD) "replaces the default shared fibre cable with a single point to point fibre cable to your site". Openreach says this means "mirrored upload and download speeds, no shared bandwidth and industry leading SLAs". Because it is sole-use, the speed is the same in both directions and is set to suit the business.

Leased line vs FTTP at a glance

The table below summarises Openreach's own comparison of EAD and FTTP. The provider you buy from sets the exact speed, repair terms and price.

Why do upload speeds matter so much?

Most office broadband decisions are made on download speed, but many modern workloads are upload-heavy: cloud backups, sending large files, video calls, hosted phone systems, remote staff connecting back into office systems, and CCTV viewed off site.

On full fibre the upload ceiling is lower than the download figure. On a leased line you choose one speed and get it in both directions. If your team regularly waits for uploads to finish, that is usually the first sign that FTTP is being stretched.

Worked example: a nightly cloud backup

This is an illustrative calculation, not a measured result. Real throughput will be lower than the line speed once network overheads, Wi-Fi and the cloud service's own limits are taken into account.

Suppose an office backs up 200GB to the cloud every night.

1. 200GB is roughly 1,600,000 megabits (200 × 8 × 1,000).
2. At full fibre's maximum upload of 220Mbps: 1,600,000 ÷ 220 ≈ 7,300 seconds, or about 2 hours, assuming the full upload speed is available all night.
3. On a 1Gbps leased line: 1,600,000 ÷ 1,000 = 1,600 seconds, or about 27 minutes.

If the backup finishes overnight either way, FTTP may be perfectly adequate. If the same uploads have to happen during the working day while staff are on video calls and a hosted phone system, the gap starts to matter.

When is a leased line worth it?

A leased line tends to make sense when one or more of these is true:

• Downtime is expensive. A repair commitment measured in hours rather than "next working day" is the main reason many firms pay for a leased line.
• You need consistent performance. Bandwidth that is not shared with other users, and guaranteed latency, suit voice, video and real-time systems.
• You upload as much as you download. Symmetrical speed suits backups, design and media files, and hosting.
• You need resilience. Openreach offers a single connection over two paths that re-routes automatically, or diversely routed circuits terminating in different parts of the building. FTTP has neither.
• You connect several sites. Ethernet can also be used as a private point-to-point link between your own premises.

When is full fibre enough?

Full fibre is usually the better value when:

• your team is small to medium and mainly browses, emails and uses cloud software;
• an outage of up to a working day would be inconvenient rather than critical;
• uploads are occasional, or large transfers can run outside office hours; or
• you can add a cheaper backup, such as a 4G or 5G router, for continuity.

Openreach also notes that full fibre is not affected by the PSTN switch-off, which Openreach says happens in January 2027, because it runs entirely on fibre and pairs with a digital phone line. If you are still on copper broadband, read our PSTN switch-off guide for businesses.

How long does a leased line take to install, and what can add cost?

A leased line normally takes longer to arrange than broadband because the route to your building has to be surveyed and, in some cases, built. Openreach offers stand-alone surveys that give providers indicative or firm prices before an order is placed.

If Openreach has to build extra infrastructure to reach your site, it can raise excess construction charges. Ask any provider whether a survey has been carried out, whether excess construction charges could apply and who pays them, before you sign. Keep the answers in writing.

Full fibre installation is simpler where fibre is already available: an engineer fits an Optical Network Terminal (ONT) and your router plugs into it. Check availability for your exact address rather than relying on a postcode.

Questions to ask before you choose

1. What upload speed do we actually need during working hours?
2. What would a day without internet cost us?
3. What repair time is written into the contract, and what compensation applies if it is missed?
4. Do we need a second, diverse route or a mobile backup?
5. Has the provider checked availability and construction costs at our address?
6. Will our phone system run over this connection after the switch-off?

Frequently asked questions

Is a leased line faster than full fibre?

Not always in download terms. Business FTTP offers up to 1Gbps download, which can match a 1Gbps leased line. The leased line's advantages are that the speed is the same in both directions, the bandwidth is not shared and it comes with a stronger repair commitment.

Is a leased line the same as dedicated fibre or Ethernet?

In everyday UK business use, yes. "Leased line", "dedicated fibre" and "Ethernet" are commonly used for the same thing: a private, uncontended fibre circuit. Openreach sells it to providers as Ethernet products such as EAD.

Can a small business get a leased line?

Yes. Openreach's own comparison lists the typical EAD customer as "corporate and SME companies dependent on high bandwidth". Whether it is good value depends on how much downtime and slow uploads cost your business compared with the higher price and longer installation.

Do I need a leased line for VoIP?

Not usually. Hosted VoIP works well on reliable business broadband with enough upload capacity for your number of simultaneous calls. Larger call volumes, or teams where losing phones for a day is unacceptable, are where a leased line or a backup connection earns its place. Our hosted VoIP guide covers the broadband side in more detail.

What does SLA mean on a leased line?

SLA stands for service level agreement: the provider's written commitment on things such as repair times and availability. Openreach describes EAD's SLA as typically five hours or less depending on product. Check the SLA your own provider offers, because that is the one in your contract.

Sources

• Openreach: Full Fibre broadband for business (speeds, installation, switch-off)
• Openreach: Broadband for business and Ethernet overview
• Openreach: Network connectivity for commercial developments, EAD vs FTTP comparison (PDF)
• Openreach: Ethernet products and stand-alone surveys
• Openreach: Excess construction charges

Related guides

• Business broadband explained
• Business phone and broadband bundles
• PSTN switch-off: what businesses need to do
• Hosted VoIP for business
• Business VoIP phone systems