How Much Does a 100Mbps Leased Line Cost? 2025 Guide

Why 100Mbps Is the Most Popular Leased Line Speed

100Mbps sits at the practical entry point for business leased lines in the UK. It provides enough capacity for 15–35 simultaneous users running a mix of Microsoft 365, VoIP calls, video conferencing, and cloud backup — without the cost premium that comes with 500Mbps or 1Gbps circuits.

For many SMEs, 100Mbps represents the point at which broadband limitations (congestion, asymmetric speeds, limited SLAs) become real business problems, and a dedicated circuit solves those problems at a manageable cost.

100Mbps Leased Line Prices in 2025

Prices vary significantly by location. The following figures reflect typical 2025 market pricing on a 36-month contract:

• Central London and major city centres: from £199–£300/month
• Regional cities (Manchester, Birmingham, Leeds, Bristol): from £220–£380/month
• Suburban commercial areas: from £300–£450/month
• Semi-rural and rural locations: from £450–£650+/month

Installation is often waived on a standard 36-month contract for sites near existing fibre infrastructure. Sites requiring new duct runs or wayleave agreements may incur charges of £500–£2,500.

What Affects the Price of a 100Mbps Leased Line?

Location

The proximity of your building to existing fibre infrastructure is the primary cost driver. Urban sites near well-established Openreach, CityFibre, or Virgin Media Business fibre routes attract lower prices because the civil engineering cost of reaching the building is minimal. Rural sites require more extensive new build and therefore cost more.

Provider and Network

In locations served by multiple networks, competition reduces prices. Where only Openreach has coverage, the price reflects the absence of alternatives. CityFibre's expanding urban footprint has meaningfully increased competition — and reduced prices — in many city centres over the past few years.

Contract Length

Standard leased line contracts run for 36 or 60 months. A 60-month term typically delivers a monthly saving of £30–£60 compared to the equivalent 36-month price. Whether that saving justifies the longer commitment depends on your confidence in the premises and bandwidth requirements over the full period.

SLA Tier

Standard 100Mbps leased lines carry a 99.9% uptime SLA and an MTTR (mean time to repair) of 5–20 hours. Enhanced SLA products offering 99.95% uptime and a 4-hour fix guarantee carry a premium of typically £30–£80 per month. For businesses where extended downtime causes significant financial impact, this premium is worth considering.

100Mbps vs 500Mbps: Is It Worth Upgrading?

The price gap between 100Mbps and 500Mbps leased lines is smaller than many assume. In well-connected areas, a 500Mbps circuit may cost only £80–£150 more per month than a 100Mbps circuit from the same provider. If your team is already at 30–40 users or growing toward that level, starting at 500Mbps avoids a mid-contract upgrade or an early termination situation.

The symmetric upload speed matters particularly: a 100Mbps leased line provides 100Mbps upload, which is transformational for organisations running large-scale cloud backup, video production workflows, or off-site server access. Broadband at the same download speed rarely exceeds 20Mbps upload.

How to Get an Accurate 100Mbps Leased Line Quote

Pre-survey estimates indicate likely pricing ranges; firm quotes come after a site survey confirms the exact civil works required. When approaching the market for a 100Mbps leased line, ask providers:

• Is this a firm post-survey price or a pre-survey estimate?
• What are the installation lead times from order to go-live?
• What happens to pricing at the end of the contract term?
• What is the exact SLA for fault response and repair?

AMVIA checks availability across multiple networks simultaneously and manages the quoting and survey process, presenting comparable post-survey firm prices from the providers that can genuinely serve your site.