The dark fibre network to meet any future business need

Building a network to support bandwidth-intensive business applications? Or creating your own backhaul network? Colt’s dark fibre network is the most extensive and reliable in Europe.  We cover 47 metropolitan areas which are interconnected by our 38,000km network. We're confident our dark fibre network will meet any future business need.


Build your business on Colt’s trusted, scalable, dark fibre network.


Dark Fibre gives you maximum control and flexibility over your network, allowing your network to scale-up as your bandwidth requirements grow – providing virtually limitless capacity.


Dark Fibre services you can trust to perform. We invest heavily in our network. Which is why we're used by many of the world's leading carriers, operators, and service providers.

Cost Effective

Dark Fibre can provide a highly cost-effective way of managing your own network, enabling you to add bandwidth as your capacity requirements increase.

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Michael John Lytle


The two things that Colt does impeccably well is providing us with a robust physical infrastructure that does exactly what it's supposed to do, with no noticeable impact on the user. The second thing is the enhanced reporting and performance analysis of our website to see what's going on in the Web environment.

Custom-designed Dark Fibre networks for metro or long-haul applications – with flexible commercial options


Our Dark Fibre networks are highly reliable. Both point-to-point and ring topologies are available – with customer-defined, geographically diverse routes for enhanced availability.


Build a dark fibre network that will meet all your coming business needs. Our solution architects are available to help from planning through to design and beyond.


Whether your requirements are for a small metropolitan network linking key sites, or for an international Dark Fibre backbone, we’re able to help plan a design around your business. We offer a range of commercial options including standard lease and IRU agreements (indefeasible rights of use).

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+44 (0) 20 7863 5510