The Complete Guide to Business Leased Lines

How Leased Lines Work

A leased line is a point-to-point connection between your business premises and a carrier's Point of Presence (PoP) on the national fibre network. The connection runs over dedicated fibre infrastructure — either Openreach's national network, or an alternative carrier such as CityFibre, Zayo, or Colt, depending on your location and the carriers present in your area.

1 Gbps leased line: £437–£994/month depending on provider and location. Alternative providers (CityFibre, Hyperoptic) cluster at £450–£550/month vs. incumbents (BT, Vodafone) at £700–£1,000/month. (AMVIA)

Area 3: 46% of UK postcode sectors — limited competition; Openreach must provide dark fibre at cost-based prices (ISPreview)

87% of IT professionals reported experiencing SaaS data loss in 2024 — with malicious deletions as the leading cause (2025 State of SaaS Backup and Recovery Report, The Hacker News). (Thehackernews)

Unlike standard broadband, where your connection shares capacity in the local access network with neighbouring properties, a leased line's bandwidth is dedicated solely to your premises. The carrier's network equipment is configured to deliver the contracted bandwidth at all times, regardless of what other customers are doing.

The physical installation typically requires a new fibre cable to be pulled to your premises, or the activation of existing fibre infrastructure if your building is already connected. This is why leased line installation takes 45–90 days in most cases — the carrier needs to survey the route, arrange any civils works, and connect your premises to their network.

Leased Line vs Broadband — Key Differences

The most important distinction is contention. Standard broadband connections are contended — your broadband bandwidth is shared across many users in your local exchange or cabinet area. During peak hours (typically 7–10pm, and increasingly during business hours as home working increases), this shared capacity is under pressure, and performance can degrade significantly.

A leased line is uncontended. The bandwidth you purchase is reserved for your use, 24 hours a day. This means your Microsoft Teams calls remain clear during Monday morning team meetings, your cloud backups complete on schedule overnight, and your ERP connection performs the same at 9am as it does at 3am.

The second key difference is symmetry. Standard broadband is asymmetric — download speeds are typically much higher than upload speeds, because residential internet usage is predominantly download-heavy. Business usage is frequently different: cloud backups, video conferencing, large file transfers, and hosted service management all require meaningful upload bandwidth. Leased lines provide identical upload and download speeds — typically described as symmetric or 1:1 contention.

The third difference is the service level agreement. Broadband comes with best-efforts service — the provider will try to resolve faults, but with limited contractual commitment on timing. A leased line SLA typically specifies fault repair within four hours (or next business day on lower-tier products), with financial credits if the SLA is missed. For businesses where connectivity is business-critical, this contractual certainty has real value.

Leased Line Speeds and Technologies

UK leased lines are available at a range of speeds, typically from 100Mbps up to 10Gbps. The most common speeds ordered by UK SMEs are 100Mbps, 500Mbps, and 1Gbps. The choice depends on the number of users, the applications you run, and your growth trajectory.

As a practical guide: a 100Mbps leased line comfortably supports 20–40 concurrent users on cloud applications and VoIP. A 500Mbps circuit supports 100–200 users. A 1Gbps circuit provides substantial headroom for most SME environments and allows for cloud backup, video surveillance, and guest Wi-Fi without contention.

The underlying technology varies by carrier and location. Ethernet over Fibre (EoF) is the most common technology for full-fibre leased lines. Some locations may still receive Ethernet First Mile (EFM) over copper, though this technology is being phased out as the fibre rollout progresses.

How Leased Line Pricing Works

Leased line pricing in the UK depends on several factors: your location (whether you are 'on-net' or 'off-net' from the carrier's existing infrastructure), the bandwidth you need, the contract term you choose, and whether you opt for a fully managed service or an unmanaged bearer.

Location has the biggest single impact on price. If your premises are already connected to a carrier's fibre network — described as being 'on-net' — the installation cost is typically low (often £0 on promotional terms) and the monthly rental is at its most competitive. If you are 'off-net', the carrier must install new infrastructure to reach you, which involves a civils survey, duct work, and potentially trenching across public roads. This can add significant one-off installation costs and increases monthly rental.

Indicatively, a 1Gbps leased line in a major UK city typically costs £350–£600 per month on a three-year contract. The same circuit in a rural area with limited carrier presence may cost £750–£1,100 per month. AMVIA's platform checks availability and pricing across multiple carriers simultaneously, so you can compare options at your specific postcode rather than relying on indicative ranges.

Contract terms of one, three, and five years are standard. Three-year terms offer the best balance of pricing and flexibility for most businesses. One-year terms carry a significant premium — typically 25–35% higher monthly cost — and are generally only appropriate for businesses with short-term premises commitments.

The Case for a Managed Leased Line Service

A leased line can be purchased as a raw bearer — the carrier provides the physical connection and a management portal, and you handle everything else. Or it can be provided as a fully managed service, where a provider like AMVIA sits between you and the carrier, managing the relationship, monitoring the circuit, and acting as a single point of contact for any issues.

The managed service model offers several practical advantages for businesses without dedicated network teams. First, fault resolution is significantly faster when your provider can open carrier tickets on your behalf, escalate appropriately, and manage the resolution process rather than requiring you to navigate the carrier's support process. Second, proactive monitoring can identify performance degradation before it becomes an outage. Third, your managed service provider can handle router configuration, firewall management, and any network changes — reducing the technical burden on your team.

AMVIA manages leased lines for over 1,200 UK business sites. Our managed leased line service includes a managed CPE router, 24/7 proactive circuit monitoring, carrier relationship management, and a dedicated account manager. We source circuits from multiple carriers — Openreach, CityFibre, Zayo, Colt, Virgin Media Business, and others — and recommend the best option for your location, budget, and requirements.

Leased Lines for Multi-Site Businesses

Businesses with multiple sites have additional considerations. Each site may be served by a different carrier depending on local fibre availability, creating a heterogeneous network that is harder to manage centrally. AMVIA's platform handles multi-carrier procurement, standardises the managed service layer across all sites, and provides centralised monitoring through AmviaIQ — giving you visibility of all your connections in one dashboard.

For businesses requiring private connectivity between sites — rather than simply internet access at each location — a managed MPLS or SD-WAN solution may be more appropriate. AMVIA designs and delivers both, depending on your traffic patterns, security requirements, and budget.

Leased Lines and Business Continuity

A leased line, by itself, is a single point of failure. If the physical fibre is cut or the carrier experiences a network fault, your connectivity is lost until the fault is repaired. For businesses where internet access is business-critical, a secondary connection — typically a 4G/5G failover or a second leased line on a diverse route — provides resilience.

AMVIA designs connectivity solutions with resilience as a standard consideration. Our managed router configurations support automatic failover between primary and secondary circuits, so that a leased line fault triggers an immediate switch to the backup connection with minimal disruption. We monitor both circuits continuously and manage the failback when the primary is restored.

Getting a Leased Line Quote

The first step to getting a leased line is running an availability check at your postcode. This identifies which carriers have infrastructure at or near your premises, their indicative pricing, and estimated installation lead times. AMVIA's quoting tool runs this check across all major UK carriers simultaneously — returning results in under 60 seconds without requiring a discovery call or site survey.

Once you have carrier options identified, the next step is a managed service proposal that specifies the circuit, router, monitoring, SLA, and any additional services you need. AMVIA provides this as a single monthly price — no separate billing for carrier and management components.