If you have asked for a leased line quote, the first question after price is almost always about time. The honest answer is that leased line installation in London usually takes anywhere from 30 to 90 working days, and occasionally longer. The wide range is not vendor evasiveness — it reflects real variables such as fibre proximity, civil works, landlord permissions and Openreach or alt-net scheduling. This guide breaks down each stage of the process so you can plan your project, avoid the common delays, and understand what a realistic go-live date looks like for your building.
The short answer: typical London lead times
For most London businesses, a standard leased line takes around 45 to 60 working days from a signed order to a working service. Sites that are already close to fibre — or in a building where a provider has existing infrastructure — can complete in as little as 20 to 30 working days. Complex sites requiring new duct, road crossings or lengthy wayleave negotiations can push beyond 90 working days.
It is worth being clear about what 'installation' means. The clock does not start when you request a quote; it starts when you place a confirmed order. Quoting, surveys and internal approvals can add days or weeks before that point, so factor those into your own timeline.
A leased line is a dedicated, symmetric connection built specifically to your premises, which is exactly why it takes longer than plugging in a broadband router. That physical build work is where the time goes.
What actually happens during installation
Understanding the stages helps you see why the timeline is what it is. Each step depends on the one before it, and any single blocker can stall the whole project.
Broadly, a London leased line install follows this sequence:
- Order placed and validated — the provider confirms address, bandwidth and the access provider (Openreach, CityFibre or another network).
- Planning and desktop survey — engineers assess the nearest fibre and the likely route into your building.
- Site survey — a physical visit to confirm the cable entry point, internal cabling route and any construction needs.
- Wayleave and permissions — legal agreement from the building owner, plus any council permits for street works.
- Civil works — digging, duct installation or road crossings if the fibre does not already reach your premises.
- Fibre installation and jumpering — the physical fibre is pulled through and connected at the exchange or aggregation node.
- Router install and commissioning — the provider configures the presentation equipment and hands over a tested, live circuit.
The biggest cause of delay: wayleaves
If a single factor derails London leased line timelines, it is the wayleave — the legal permission from a landlord or freeholder allowing the provider to install and maintain cabling on their property. In multi-tenant offices, which are extremely common in London, this can be the longest single step.
Some managing agents turn a wayleave around in days. Others take weeks, request legal review, or want signatures from a freeholder who is slow to respond. Because the provider cannot begin internal works without it, a stalled wayleave can add a month or more with no way to accelerate the physical build.
The practical fix is to start early. As soon as you have decided to proceed, identify your building's managing agent and freeholder, and ask your provider for the wayleave paperwork so you can begin that conversation in parallel with the survey rather than after it.
Civil works and why some sites take longer
If there is no existing fibre or spare duct capacity to your building, engineers may need to carry out civil works — excavating pavement, installing new ducting, or crossing a road. In central London these works require permits from the local authority and are subject to traffic management rules, which adds scheduling time regardless of how quickly the physical digging could be done.
Sites in shared business parks, listed buildings, or premises set back from the main road frequently need more construction than a ground-floor unit on a fibre-rich high street. The desktop survey usually gives an early indication, but the site survey is where any construction requirement is confirmed.
Where civils are needed, a provider may quote 'excess construction charges' and the timeline extends accordingly. This is normal and not a sign of a problem — but it is the point at which a 45-day project can become a 90-day one.
How to choose a service that fits your timeline
If your move-in date is fixed and tight, product choice matters. A full fibre leased line offers the best performance but the longest possible lead time. If you need connectivity sooner, discuss the options with your provider up front.
Where speed is critical, a temporary solution can bridge the gap while the permanent circuit is built. Options worth raising include:
- A 4G/5G mobile broadband service as an interim connection during the build.
- Backup connectivity that also serves as a stopgap, then remains for resilience once the leased line is live.
- An FTTP leased line where full ducted fibre is not yet available but a faster-to-deliver product suits your needs.
- SD-WAN to combine circuits intelligently across one or more sites while the primary line is provisioned.
Multi-site and central London considerations
Organisations connecting several premises should not assume a uniform timeline. Each site has its own fibre proximity, landlord and permit picture, so a five-site rollout will complete in waves rather than all at once. Sequencing the order — starting with the sites most likely to face delays — keeps the overall project moving.
Central London postcodes are often better served by existing fibre than outer boroughs or industrial estates, which can shorten timelines. However, dense central areas also carry stricter street-works restrictions, so the advantage is not universal. Good network consultancy at the design stage helps you predict which sites will be quick and which need early attention.
For distributed businesses, planning multi-site connectivity as a single coordinated programme — rather than ordering each line separately — gives you one point of accountability and a clearer combined go-live schedule.
Practical steps to keep your install on track
You cannot control Openreach scheduling or the weather, but you can remove the delays that are within your control. In our experience, the projects that land on time are the ones where the customer engaged early on permissions and access.
A few habits make a measurable difference:
- Confirm your building's managing agent and freeholder details before you place the order.
- Request and progress the wayleave in parallel with the survey, not after it.
- Nominate a single internal contact who can approve access and answer engineer queries quickly.
- Ensure a comms room or cabinet location is agreed and accessible for the site survey and install day.
- Order any structured data cabling or internal network changes so they are ready when the circuit goes live.
- Ask for regular milestone updates so you can spot a stalled stage early.
So, what date should you plan around?
For budgeting and diary purposes, plan for 60 working days from order to go-live for a typical London site, and treat anything faster as a bonus. If you know your building already has fibre and a straightforward wayleave, 30 days is realistic. If you are in a complex or newly built site, allow up to 90 days and keep an interim connection ready.
The single best thing you can do is start the conversation before you need the line. A short scoping call lets a provider run a desktop check on fibre availability at your postcode and flag likely construction or wayleave issues before you commit.
If you would like a realistic timeline for your specific address, our team can check availability and outline the likely stages — get in touch or read more about our leased line and dedicated internet access services.