What Is a Leased Line? A Plain-English Guide for UK Businesses

What Is a Leased Line?

A leased line — also called an Ethernet leased line, dedicated internet access (DIA), or private circuit — is a dedicated internet connection provided exclusively to a single business. Unlike standard broadband, which is a shared service where many businesses and homes use the same physical exchange infrastructure simultaneously, a leased line is yours alone. The bandwidth is not shared, contended, or affected by what other businesses in your area are doing.

Leased lines are point-to-point connections: a dedicated fibre circuit runs from your premises directly to the carrier's point of presence, and from there to the internet. This dedicated path is what makes leased lines fundamentally different — and in many cases fundamentally better — than broadband for business use.

Leased Line vs Broadband: Key Differences

The differences between a leased line and a business broadband connection go beyond speed. The core distinctions that matter for business use are:

• Uncontended bandwidth: The speed you pay for is the speed you get, at all times. No slowdown during peak hours. No sharing with neighbours or other businesses on the same exchange.
• Symmetric speeds: Upload and download speeds are equal. A 100 Mbps leased line delivers 100 Mbps in both directions. Broadband is asymmetric — typically much slower on upload.
• Static IP address: A leased line comes with a block of static public IP addresses allocated exclusively to your business, essential for VPN, firewall whitelisting, and cloud access policies.
• SLA with compensation: Leased lines include a service level agreement guaranteeing uptime (typically 99.9% or higher) with financial compensation if the target is missed. Broadband SLAs are typically best-efforts with no compensation.
• Dedicated support: Leased line faults are treated as priority issues with faster response and resolution targets than residential or standard business broadband faults.

Leased Line Speed Options

UK leased lines are available from 10 Mbps up to 10 Gbps, with the most common speeds for SMEs being 100 Mbps, 500 Mbps, and 1 Gbps. The right speed depends on the number of users, the nature of the workloads, and the type of services running over the connection.

As a rough guide: a 100 Mbps leased line comfortably supports 30–50 office workers using cloud applications and VoIP; a 500 Mbps line suits 100–200 users or businesses with heavy cloud data transfer requirements; a 1 Gbps line supports larger organisations or those running hosted infrastructure, cloud-based ERP systems, or large file transfers as routine business operations.

Because leased lines are symmetric, upload speed matters as much as download. Businesses backing up to cloud storage, using hosted phone systems, or running video conferencing at scale benefit particularly from the symmetric bandwidth that broadband cannot provide.

Leased Line Costs in the UK

Leased line costs vary significantly based on location, speed, and provider. As a guide for 2026 UK pricing:

• 100 Mbps: Approximately £200–£400 per month in urban areas; up to £500 in semi-rural areas
• 500 Mbps: Approximately £300–£600 per month
• 1 Gbps: Approximately £437–£994 per month depending on provider and location

Prices are typically quoted on 36-month terms. Shorter terms are available but at higher monthly cost. Installation costs (the one-time charge to build the circuit to your premises) vary — urban locations with existing carrier infrastructure close by can have zero or low installation costs, while rural or hard-to-reach sites may incur significant excess construction charges (ECCs).

Installation Time

Leased line installation typically takes 30 to 90 days from order to go-live. The variable is how much civil engineering work is required to bring fibre to your premises. In established business parks and city centre locations where carriers already have infrastructure nearby, installations are typically faster. In rural or remote locations, new fibre may need to be laid, extending the timeline.

Businesses should plan connectivity changes well in advance of any deadline — whether that is a new office opening, a lease renewal, or the end of a broadband contract. AMVIA advises starting the leased line procurement process at least 60 days before the required go-live date.

SLA and Uptime Guarantee

A leased line SLA typically guarantees 99.9% or higher availability, equivalent to less than nine hours of unplanned downtime per year. Unlike broadband, where SLAs are largely symbolic, leased line SLAs include financial compensation — typically a refund of monthly rental charges for periods of downtime that breach the guaranteed targets.

More importantly, leased line SLAs specify response and fix times: a typical business leased line includes a four-hour response target and a next-business-day fix target, with enhanced SLAs available offering four-hour fix guarantees for businesses where downtime carries significant financial consequences.

Who Needs a Leased Line?

A leased line is appropriate for any business where reliable, high-performance internet connectivity is critical to operations. Practical indicators include: 20 or more staff sharing a single internet connection; heavy use of cloud applications including Microsoft 365, hosted phone systems, or cloud-based ERP; on-site servers or hosted infrastructure that staff access remotely over VPN; video conferencing as a daily business requirement; or any compliance or contractual requirement for a guaranteed bandwidth and SLA.

AMVIA provides leased lines from all major UK carriers — including BT Openreach, Virgin Media Business, CityFibre, and Zayo — compared and sourced to give UK businesses the best combination of price, performance, and SLA for their location. Contact AMVIA on 0333 733 8050 for a no-obligation leased line quote.