Leased Line vs Broadband for Cardiff Businesses: Which Do You Actually Need?

September 6, 2026

Leased Line vs Broadband for Cardiff Businesses: Which Do You Actually Need?

Leased Line vs Broadband

Most Cardiff offices start on business broadband because it's cheap and easy. Then the video calls drop, the cloud phone system stutters, and someone asks whether a leased line is worth the extra money.

Here's the difference without the sales fog.

Broadband is shared. A leased line is yours.

Business broadband rides the same pipes as everyone else on the street. At 9am and 5pm, speeds dip. That's fine for email and browsing. It's not fine for a VoIP system, cloud backups, or a warehouse scanning stock all day.

A leased line is a dedicated fibre circuit between your office and the exchange. The speed you buy is the speed you get, up and down, all day. Typical Cardiff installs are 100 Mbps, 200 Mbps, or 1 Gbps.

What it costs in 2026

Business broadband: often £30 to £80 a month, plus a cheap router.

A 100 Mbps leased line in South Wales: typically £200 to £400 a month on a three-year term, plus install. Faster circuits cost more. Install can take six to twelve weeks because Openreach or the fibre provider has to build the last stretch.

When broadband is enough

  • Under ten staff
  • Mostly email, web, and light cloud tools
  • You can live with the occasional slow afternoon
  • You're not running a hosted phone system that needs clean upload

When a leased line pays for itself

  • Cloud phone system or call centre
  • Regular large file transfers or backups
  • Multiple sites that need to stay connected
  • You can't afford an hour of downtime when a shared line congests

A dropped call on a cheap line costs more than the monthly difference if that call was a customer.

The hybrid a lot of Cardiff firms use

Keep broadband as a backup. Put voice and critical apps on the leased line. If the dedicated circuit ever fails, phones fail over. That's the setup we install most often.

What to ask a provider

  1. Is this a true leased line or "so-called dedicated" broadband?
  2. What's the guaranteed upload speed, not just download?
  3. What's the SLA — four hours, next business day?
  4. Who owns the last-mile fibre, and who do I call at 2am?
  5. Can you bond it with my existing broadband for failover?

Bottom line

If your phones and cloud tools already work, stay on broadband and spend the money elsewhere. If calls drop when the office fills up, a leased line isn't a luxury — it's the pipe your business is already trying to use.

Crystal Voice Data designs voice and data together, so the line and the phone system don't fight each other. Based in Cardiff, we cover South Wales for leased lines, Wi-Fi, VoIP, and cabling.

Want a straight comparison against what you're paying now? Get in touch and we'll price both options.

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