The Ultimate Guide to 100Mbps Leased Line Costs

What Is a 100Mbps Leased Line?

A 100Mbps leased line is a dedicated, uncontended fibre circuit delivering symmetrical 100Mbps upload and download speeds directly to your premises. Unlike standard business broadband, the bandwidth is not shared with neighbouring properties — your 100Mbps is yours alone, 24 hours a day.

This distinction matters enormously for businesses that rely on cloud applications, VoIP calls, large file transfers, or remote working infrastructure. When broadband slows down at peak times, a leased line does not. That consistency is what businesses are paying for.

What Does a 100Mbps Leased Line Cost in the UK?

Pricing varies considerably based on your location and the infrastructure available nearby. The following ranges reflect realistic 2025 market pricing across the UK:

• City centre locations (e.g. London, Manchester, Birmingham): from £199 to £350 per month
• Suburban and edge-of-town sites: from £300 to £500 per month
• Rural and remote locations: from £450 to £700+ per month

These figures assume a standard 36-month contract. Shorter terms cost more; longer terms of 60 months can reduce the monthly figure further. Installation charges, where applicable, typically run between £0 and £1,000 depending on the provider and the site survey outcome.

What Drives the Cost?

Distance from the nearest exchange or duct

The further your building sits from the provider's nearest fibre node or exchange, the more civil engineering is required to reach you. A site in a managed office park in a city centre, close to existing fibre infrastructure, will almost always attract a lower quote than an isolated building on a trading estate outside town.

Wayleave agreements

If the fibre needs to cross third-party land — private car parks, shared access roads, or another business's property — a wayleave agreement must be secured. These can add weeks to the installation timeline and in some cases push costs up significantly.

Provider network coverage

Not every provider has active infrastructure in every postcode. Openreach has the widest UK reach, but CityFibre, Virgin Media Business, and Zayo are strong alternatives in specific cities and industrial areas. Where only one provider can reach your site, expect less competitive pricing.

Contract length

Standard contract terms for leased lines are 36 or 60 months. Moving from a 36-month to a 60-month term often reduces monthly costs by 10–20%. However, committing for five years requires confidence that the bandwidth and the premises will remain suitable for that period.

What SLA Should You Expect?

A service level agreement (SLA) defines the provider's obligations on fault resolution and uptime. For a 100Mbps leased line, you should expect:

• Uptime guarantee: 99.9% or above (some providers offer 99.95%)
• Mean time to repair (MTTR): 5–6 hours for priority customers; up to 20 hours for standard service
• Contention ratio: 1:1 — fully uncontended
• Symmetric speeds: 100Mbps both ways

Always check the SLA document carefully, not just the headline claims. Some providers advertise a 5-hour MTTR but deliver it only within business hours, which effectively extends fault resolution to the next working day for out-of-hours failures.

How to Compare Quotes Effectively

Getting multiple quotes is straightforward but comparing them fairly requires looking at several factors simultaneously:

• Monthly rental vs. total contract cost: A lower monthly price on a 60-month term may cost more over five years than a higher monthly price on a 36-month term.
• Installation lead time: Standard installation takes 45–90 working days. If a provider quotes significantly faster delivery, check whether they have infrastructure nearby or are simply being optimistic.
• Escalation process: Ask what happens when the SLA is breached. Service credits are standard, but some providers offer more generous compensation than others.
• Resilience options: Can the provider offer a diverse second circuit or a 4G/5G failover connection? For business-critical sites, this matters.

AMVIA works with multiple Tier 1 and Tier 2 providers across the UK and runs postcode-level availability checks to identify which networks can serve your site before issuing quotes. This avoids the common problem of receiving a low estimate that increases after the site survey reveals additional civil works are required.

Is 100Mbps the Right Speed for Your Business?

100Mbps suits businesses with 10 to 40 simultaneous users who rely on cloud-hosted applications, Microsoft 365, VoIP, and video conferencing. Beyond that user count, or for businesses running on-premises servers with heavy backup traffic, a 500Mbps or 1Gbps circuit is worth considering — the price difference is smaller than most assume.

A useful rule of thumb: allow 2–4Mbps per user for general cloud and VoIP use. A team of 30 people therefore needs a minimum of 60–120Mbps of headroom, making 100Mbps the sensible floor rather than a generous provision.