Your office internet usually shares local capacity with the buildings around you. When that neighbourhood gets busy, everyone slows down. A leased line gives your site its own fibre circuit. Nobody else uses that bandwidth.
What is a leased line?
A leased line is a fibre path from your building into the carrier's network, with matching upload and download capacity. The bandwidth is uncontended: it isn't divided among nearby offices or homes.
The service includes:
- Matching upload and download. The same speed in both directions.
- Bandwidth that stays available. The rate you buy is there day and night.
- A contractual uptime SLA. Commonly 99.9%, with financial penalties if the carrier misses it.
- Static IP addresses. Required for VPNs, hosted services and many cloud setups.
How it differs from standard broadband
Standard broadband, FTTP included, is a contended product. The provider sells more capacity than the local network can deliver at once, because they assume not every customer will be active together. That assumption holds for a household. In an office it produces slowdowns when other local users come online.
A leased line performs the same at 9am on a Monday as it does at 3am on a Saturday.
Who needs a leased line?
A dedicated circuit is worth considering when:
- Ten or more people using Microsoft 365, a CRM or hosted telephony
- Voice sitting on the internet. Business VoIP needs a stable, low-latency link.
- Workloads living in the cloud. Azure, AWS and hosted line-of-business applications all depend on consistent access.
- Lost connectivity stops the operation. Staff can't reach the systems they need.
- You're sending more than you receive. Ordinary broadband is slower on the upload, which holds up file transfers and backups.
Why automation needs a steady circuit
Workflow automation sends jobs across the same connection your staff already use. If that connection slows at 10am, the automated work slows with it.
How much does a leased line cost in the UK?
The monthly figure depends on your address, the speed you need and which carrier can reach the postcode. As a working guide:
- 100Mbps: £200–£350 a month
- 500Mbps: £350–£500 a month
- 1Gbps: £500–£800 a month
Install is usually free or folded into a 12–36 month contract. Delivery commonly takes 30–45 working days.
What's the installation process?
- Postcode check. We look at every carrier that can serve the site and shortlist the workable options.
- Site survey. The chosen carrier inspects the building and confirms the fibre route.
- Wayleave, if required. Formal consent to take fibre across land you do not own.
- Installation. Fibre is brought into the premises and terminated on a network interface device.
- Testing and handover. We check the circuit against the SLA before you go live.
Alternatives to a leased line
If a dedicated circuit is more than you need today:
- FTTP fibre broadband. Lower monthly cost, but the capacity is shared and upload is slower than download.
- SD-WAN with broadband failover. Keep a leased line as the main path, with a cheaper broadband circuit standing by.
- Broadband with 4G failover. The lowest-cost way to keep a backup path if the main circuit fails.
What to do next
Wanzo compares leased line options from more than 30 UK carriers, based on your postcode and how the office uses the internet. Tell us about the site and we'll come back with a recommendation within 48 hours. leased lines](/internet-services/leased-lines) page.