Both connect you to the internet — but they behave very differently. This comparison breaks down where each wins, so you can match the right connection to how your business actually works.
Head-to-head
The table below summarises the main differences. For a fuller technical breakdown of the options, our connectivity and telecoms team can help you weigh each factor against your day-to-day usage.
The key distinctions come down to four factors. Bandwidth on broadband is contended, meaning you share capacity with other users in your area and speeds can dip at busy times; a leased line gives you a dedicated, uncontended connection. Broadband is usually asymmetric, with fast download but much slower upload, while a leased line is symmetric — the same speed both ways. Broadband is sold on a best-efforts basis with no guaranteed fix time, whereas a leased line comes with a Service Level Agreement covering uptime and response. Finally, broadband is provisioned quickly and cheaply, while a leased line costs more and can take weeks to install.
When broadband is enough
For very small teams, low cloud reliance and a tolerance for the occasional slow spell or outage, full-fibre (FTTP) broadband offers excellent value and increasingly strong speeds. It's a sensible choice when downtime is an inconvenience rather than a cost.
It also suits businesses whose work is largely offline, or where staff can continue on mobile data if the line drops. Bear in mind that FTTP is not available everywhere yet — some premises still rely on slower FTTC (fibre to the cabinet), so it's worth checking what can actually be delivered to your address before assuming full fibre is an option.
When you need a leased line
If your team relies on cloud apps, runs VoIP, moves large files, or simply can't afford to be offline, a leased line's dedicated bandwidth and SLA pay for themselves. The symmetric upload alone transforms video calls, backups and hosting. A dedicated connection also underpins reliable cloud hosted PBX telephony, where jitter and dropped calls quickly become a business problem. If you're based in the capital, our leased lines in London coverage is worth reviewing when comparing providers.
When budgeting, look beyond the headline monthly cost. Consider the guaranteed fix times in the SLA, whether the bandwidth is scalable without a new install, and how quickly the provider can restore service if the line fails. For businesses that take payments, host their own systems, or depend on always-on cloud platforms, the cost of a single day's downtime often exceeds the annual premium of a leased line.
A middle path
Many businesses run full fibre as their primary connection with a second link or 4G/5G failover for resilience, then move to a leased line as they grow. For organisations with several offices, multi-site connectivity options can tie everything together consistently. There's no single right answer — only the right fit for your risk and budget.