The Complete Guide to Business Leased Lines

What Is a Business Leased Line?

A leased line — sometimes called an Ethernet leased line or EFM (Ethernet in the First Mile) at lower speeds — is a private telecommunications circuit that connects your premises directly to an internet exchange point. Unlike standard business broadband, a leased line is:

• Dedicated: The bandwidth is reserved exclusively for your business. No other customer shares it.
• Symmetric: Download and upload speeds are identical. A 500Mbps leased line delivers 500Mbps in both directions simultaneously.
• SLA-backed: Carriers provide a formal uptime guarantee, typically 99.9% or better, with defined fix times and financial remedies for failure.
• Uncontended: Performance does not degrade at busy times because there is no contention with other users.

The physical connection is typically a fibre optic cable running from a local carrier point of presence (PoP) to your premises. In areas covered by full-fibre networks such as CityFibre or Openreach's Ethernet network, installation is straightforward. In less well-served areas, alternative access technologies may be used.

How Leased Lines Work

When you order a leased line, the carrier engineers a physical connection from your premises to their network. The key components are:

1. Last mile: The physical cable from your building to the nearest network node or exchange. This is where most of the installation complexity and cost lies.
2. Carrier network: The national fibre backbone that carries your traffic to an internet exchange.
3. Internet exchange: Where the carrier's network connects to the wider internet.
4. CPE (Customer Premises Equipment): A router or switch installed at your site, usually supplied by the carrier or your managed service provider, which terminates the connection and provides your LAN with internet access.

AMVIA manages the entire chain — from ordering through the right carrier for your location, to configuring the CPE, to monitoring the circuit after go-live using AmviaIQ.

Available Speeds

Modern Ethernet leased lines are available in standardised speed tiers. The right speed for your business depends on the number of users, the applications you run, and whether you need headroom for growth.

Costs vary considerably by location. Buildings in city centres with strong carrier coverage will achieve the lower end of each range. Rural or more complex sites may cost more. AMVIA runs a multi-carrier comparison at the quotation stage to identify the most competitively priced option for each specific address.

SLAs Explained

The service level agreement attached to a leased line circuit is one of its most important features — and one that many buyers fail to scrutinise closely enough. Key SLA components to evaluate:

Availability Guarantee

Expressed as a percentage per calendar month. 99.9% availability equates to a maximum of approximately 43.8 minutes of downtime per month. Better carriers offer 99.95% or better. Always check how availability is calculated — some carriers exclude scheduled maintenance from downtime figures.

Mean Time to Repair (MTTR)

The carrier's contractual commitment to restore service following a fault. Standard MTTR for business leased lines is typically 5–7 working hours for faults within the carrier's network. Faster repair SLAs (e.g., 4 hours) are available at a premium and are worth considering for businesses with high sensitivity to downtime.

Compensation

Most carriers provide credit against future invoices when SLA targets are missed. The mechanism and amounts vary. Read the small print: some credits require active claim submission and apply only when the missed SLA is clearly attributable to the carrier.

Proactive Monitoring

AMVIA monitors all leased line circuits via AmviaIQ, which detects degradation and outages automatically and opens fault tickets with carriers without waiting for client reports. This shortens the time from fault to resolution.

Leased Line vs Alternatives

Before committing to a leased line, it is worth understanding where it sits relative to other connectivity options.

vs Full Fibre Broadband (FTTP)

Full fibre broadband (e.g., BT Full Fibre, CityFibre business products) offers gigabit download speeds at a fraction of leased line pricing — often £40–£80 per month for 1Gbps downstream. However, upload speeds are asymmetric (typically 100–200Mbps on a 1Gbps product), it is a shared contended service, and there is no equivalent SLA. For businesses that upload large files, run hosted servers, or operate VoIP at scale, the upload limitation is significant.

vs SOGEA / ADSL

Legacy broadband products (SOGEA, FTTC) are inadequate for most modern SME workloads. They are contended, asymmetric, slower, and have no meaningful uptime SLA. If your business is still on standard broadband and running cloud applications, a leased line or at minimum full-fibre broadband upgrade is overdue.

vs SD-WAN with Broadband

For multi-site businesses or those seeking cost-effective resilience, SD-WAN that bonds multiple broadband circuits or combines broadband with a leased line can deliver near-leased-line reliability at lower cost. This is not a direct substitute for a dedicated leased line, but it is a legitimate architectural choice for some businesses. AMVIA designs and manages SD-WAN solutions alongside leased line circuits.

vs Mobile/4G Failover

4G and 5G connectivity can serve as cost-effective failover for leased line circuits, ensuring continuity during fibre faults. AMVIA typically recommends building a failover solution at the same time as a leased line is installed, rather than waiting for the first outage.

The Installation Process

Understanding the installation process helps set realistic expectations with your team and avoid operational disruption.

Stage 1: Survey and Feasibility (1–5 working days)

Once you have agreed a quote, the carrier conducts a desktop feasibility survey to assess whether fibre can be delivered to your premises without complex civil engineering works (known as "excess construction charges" or ECCs). The majority of sites in urban and suburban locations are feasible at standard pricing. Rural or complex sites may attract additional charges, which AMVIA will communicate before you commit.

Stage 2: Order Placement and Lead Time (30–60 working days)

After feasibility, the order is placed with the carrier. Standard lead times are 30–45 working days for most sites, though complex installations — particularly those requiring new duct runs or Wayleave agreements from landlords — can take longer. AMVIA manages the order process and keeps you informed of progress.

Stage 3: Physical Installation

A carrier engineer installs the external cabling to your premises and places the Network Termination Equipment (NTE) — the point at which the carrier's network ends and your internal network begins. This typically requires one half-day on site.

Stage 4: CPE Configuration and Testing

AMVIA configures the Customer Premises Equipment (router), connects it to your internal network, and tests speeds and performance against the contracted specification. We configure monitoring via AmviaIQ at this stage.

Stage 5: Go-Live and Handover

The circuit is activated, and AMVIA provides confirmation of speeds and SLA terms. Where the leased line is replacing an existing connection, we manage the cutover to minimise disruption.

Who Needs a Leased Line?

A leased line is not the right solution for every business. The following factors indicate that a leased line is worth evaluating seriously:

• 20+ users relying on cloud applications: Microsoft 365, Google Workspace, Salesforce, hosted VoIP, and similar services all require consistent upload and download bandwidth. Performance issues at peak times are a strong indicator that contended broadband is the bottleneck.
• VoIP phone system: Voice quality is highly sensitive to latency, jitter, and packet loss. A dedicated circuit with a fixed SLA removes the single most common cause of VoIP call quality problems.
• Regular large file transfers: Design agencies, engineering firms, media companies, and businesses running cloud backups benefit significantly from high, symmetric upload bandwidth.
• Hosted servers or infrastructure: If you host any services that external users or other offices need to access, upload speed is as important as download speed.
• Financial services, legal, or healthcare: Regulated sectors where system availability has compliance and commercial consequences warrant the additional reliability of a dedicated circuit.
• Business-critical internet dependency: If your business cannot function without internet access for more than a short period, a leased line SLA provides measurable protection that broadband does not.

Choosing the Right Provider

The leased line market in the UK is served by several major carriers and a large number of resellers. Key considerations when evaluating providers:

Carrier Coverage at Your Address

Different carriers have stronger network coverage in different areas. CityFibre, for example, has an extensive metropolitan fibre network that can deliver competitive pricing in the cities they cover. Openreach's Ethernet network covers more of the UK. AMVIA accesses multiple carriers and runs a comparison for each client address, rather than routing all orders through a single network.

SLA Tier and MTTR Commitments

Compare SLAs on like-for-like terms. A 99.9% uptime guarantee with a 5-hour MTTR is meaningfully different from one with a 24-hour MTTR. For business-critical connectivity, MTTR is often more important than the headline availability percentage.

Support Quality

When a leased line develops a fault, you need to be able to reach someone capable of acting on it quickly. AMVIA's NOC handles fault reporting to carriers and escalation management on clients' behalf — clients are not left navigating carrier support queues alone.

Carrier Diversity

For maximum resilience, some businesses use circuits from two different carriers on physically separate routes. AMVIA can design and manage dual-carrier connectivity where required.

Cost Breakdown

Leased line pricing has two components: the monthly recurring charge (MRC) and, in some cases, a one-off installation charge.

Monthly Recurring Charge (MRC)

This is the ongoing cost for the circuit, typically quoted on a 12, 24, or 36-month contract term. Longer terms generally attract lower monthly pricing. AMVIA presents options across term lengths so clients can make an informed commercial decision.

Installation / Connection Charge

Many carriers waive the standard installation charge on contract terms of 24 months or longer, or include it as part of a managed service arrangement. Where an installation charge applies, AMVIA will quote it explicitly upfront.

Excess Construction Charges (ECCs)

Where a new fibre duct needs to be laid to reach your premises, the carrier may impose ECCs. These are site-specific and can range from a few hundred pounds to several thousand for complex routes. AMVIA includes a survey stage in every leased line order to identify ECC exposure before you commit.

CPE and Management

The cost of the router and ongoing circuit management is included within AMVIA's managed service arrangement. Clients are not billed separately for CPE in most cases — confirm this in your proposal.

Working with AMVIA on a Leased Line

AMVIA provides end-to-end management of business leased lines, from initial site survey and multi-carrier comparison through to installation management, post-live monitoring, and fault escalation.

Our approach differs from buying direct from a single carrier in two key respects. First, we have access to multiple carrier networks and can present genuinely competitive options for your specific address. Second, as your MSP, we manage the leased line as part of your wider IT environment — it is monitored via AmviaIQ alongside your endpoints, cloud services, and security posture.

Most AMVIA leased line clients receive a tailored quote within 24 hours of submitting a request. Installation is managed without requiring significant time commitment from the client's IT or facilities team.