In short
A leased line and FTTP full fibre broadband can both run on fibre to your premises. The difference is that FTTP broadband shares network capacity between customers, often has lower upload than download and is usually best efforts, while a leased line such as BTnet is dedicated, symmetrical and backed by BT's SLA, including a latency commitment.
Not sure which suits you?
Tell us about your sites and how you use the internet and we will explain whether it fits, and why.
Fibre is not the difference
"Fibre" describes the cable, not the service. FTTP (fibre to the premises), often called full fibre, means fibre runs all the way into your building rather than stopping at a street cabinet. BT's terms describe GEA over FTTP as a pure fibre access technology running from the exchange direct to the premises.
A leased line is also delivered over fibre. So the question "leased line vs fibre" really means "dedicated service vs shared service". Two businesses on the same street can both have fibre to their door and get very different results at busy times, because one is sharing capacity and the other is not.
Shared vs dedicated
Full fibre broadband is normally built on a shared design: fibre capacity from the exchange is shared between a number of premises, and capacity further into the network is shared again. That keeps the cost down and works well most of the time, but every customer on the shared parts competes for capacity when it is busy.
A leased line gives your site its own access line and reserves the bandwidth you buy. BT's terms list uncontended, symmetrical bandwidth as standard on BTnet, and BT's help pages describe it as 100% uncontended and dedicated. See contended vs uncontended.
Side-by-side comparison
This compares the two technologies. The right-hand column describes BTnet under BT's terms.
| FTTP full fibre broadband | Leased line (BTnet) | |
|---|---|---|
| Fibre to the building | Yes | Yes |
| Capacity | Shared between customers | Dedicated and uncontended |
| Upload vs download | Often lower upload, depending on the package | Symmetrical: the same both ways |
| Service levels | Usually best efforts | BT's SLA with service credits for availability, on-time delivery and latency |
| Latency commitment | Not usually | Average round trip of 20ms or less on BT's UK core network |
| Static IP addresses | Varies by package | Static IPv4 addresses as standard |
| Speeds | Set by the package | Port speeds from 2Mbps to 10Gbps, flexible within the bearer |
| Installation | Usually quicker where full fibre is already built | Survey first; BT says up to 70 working days, survey dependent |
| Cost | Lower | Higher; ask us for a quote |
See leased line vs broadband for the same comparison against broadband generally.
Still not sure? Ask us
Tell us what matters most to you and we will explain the trade-offs.
Upload, latency and service levels
Three things tend to decide it for businesses:
- Upload. Video meetings, cloud sync, backups and CCTV all send data out. BTnet's bandwidth is symmetrical, so upload is not a bottleneck. See symmetrical speeds.
- Latency. BT's SLA for BTnet includes a latency commitment: an average round trip of 20ms or less on BT's UK core network and 95ms or less transatlantic, measured over a calendar month, with service credits if missed in two consecutive months. See leased line latency.
- Service levels. BT's terms set a 100% availability service level for BTnet (excluding Wi-Fi), with credits of one day's rental per hour of downtime up to 10 hours a quarter, plus on-time delivery credits. See the BTnet SLA.
BT also says it prioritises voice traffic on BTnet and uses Direct Private Peering to Microsoft, Apple, Google and Amazon, which helps calls and cloud apps. See a leased line for VoIP and a leased line for Microsoft 365 and cloud apps.
Can BTnet run over FTTP?
Sometimes, yes. BT's terms list GEA over FTTP access as one of the access bearer types for BTnet, alongside 100Mbps, 1Gbps and 10Gbps Ethernet fibre bearers. Where BTnet uses an FTTP access bearer, it is still BTnet under BT's terms, but some details differ: one-off charges are set by bearer type, and BT treats any move of an FTTP-delivered service, even within the same site, as an external move. See moving office with a BTnet leased line.
Whether an FTTP access bearer is offered at your address, and what speeds and options come with it, is something BT confirms at quote. We can tell you what is available and explain the trade-offs before you order. See leased line bearers.
Weighing it up?
We can look at your sites and requirements and give you a straight answer.
When FTTP is enough, and when to choose a leased line
FTTP broadband is often a good fit for small teams with modest upload needs who can live with occasional slowdowns and want a quick, lower-cost install.
A BTnet leased line makes sense when:
- Many people rely on calls, video and cloud apps at the same time
- You upload a lot: backups, large files, CCTV footage, design or media work
- You want commitments on availability and latency in the contract
- You need static IP addresses for VPNs, servers or remote access
- You expect to grow and want to flex bandwidth without a new line
Read advantages and disadvantages of a leased line for the honest trade-offs, including lead times and minimum terms.
Questions to settle before you decide
A few practical questions usually make the choice clear:
- What uploads at your busiest moment? Count calls, video meetings, cloud sync, backups and cameras running at once.
- What does an hour offline cost? If the answer is lost sales, idle staff or missed calls, contracted service levels and resilience start to matter.
- Do you need static IP addresses? VPNs, remote access, servers and supplier allow-lists often do. BTnet includes static IPv4 addresses as standard.
- How soon do you need it? Full fibre broadband can often go live sooner. A leased line needs a survey, and BT says installation can take up to 70 working days, so plan ahead. See lead times.
- Will you grow? A leased line on a bearer with headroom can be flexed up without a new install.
If most answers point towards dependable, dedicated capacity, BTnet is the stronger fit. Our questions to ask before you order checklist covers the BTnet-specific details.
Get a straight answer for your site
If you are deciding between full fibre broadband and a leased line, we can look at how your business uses the connection and what is available at your address. As an Authorised Supplier for BT, we can then prepare a BTnet quote if it is the right fit, with the speed, plan and options that suit you. Contact us with your postcode.
Why buy BTnet from Forever Communications
Forever Communications is part of Forever Group and an Authorised Supplier for BT. We supply BTnet, BT's dedicated leased line internet service, to businesses, schools, charities and public sector organisations, and we help with each step from first enquiry to go-live.
- The right BTnet option for you: we help you choose a speed, bearer, router and resilience option that fits how your sites actually work, from BTnet plans to BTnet speeds
- A clear quote: BTnet is priced per site, so we check availability at your address and set out what is included; see leased line cost
- Installation managed with you: we explain the survey, any wayleave or construction steps and the installation process, and keep you updated on progress
- Connected services in one conversation: phones with BT Cloud Voice, Wi-Fi, firewalls and backup lines, so the whole set-up is planned together
- Help after go-live: we can help with faults, changes and upgrades, with the support arrangements confirmed in your quote
BTnet is a business service. Service levels, lead times and features are BT's and are confirmed at order.
Frequently asked questions
Is a leased line the same as full fibre?
No. Both can use fibre to your building, but full fibre broadband shares capacity between customers and is usually best efforts, while a leased line is dedicated, symmetrical and comes with service levels.
Is FTTP as good as a leased line?
FTTP can offer high download speeds at a lower cost, and suits many small businesses. A leased line adds dedicated capacity, symmetrical speeds and contracted service levels, which matter when the business depends on the connection.
Is a leased line fibre?
Modern leased lines are delivered over fibre. BTnet uses Ethernet fibre access bearers, and in some cases a GEA over FTTP access bearer, as confirmed at quote.
Does FTTP have symmetrical speeds?
It depends on the package. Many full fibre broadband packages have a lower upload than download speed. BTnet bandwidth is symmetrical as standard.
Is FTTP covered by a service level agreement?
Broadband is usually sold on a best-efforts basis. BTnet comes with BT's SLA covering availability, on-time delivery and latency. See the BTnet SLA.
Still deciding?
Ask us and we will reply by email with a straight answer.