FTTC Speeds Explained: What Can Your Business Expect?

FTTC — fibre to the cabinet — is still one of the most widely used broadband technologies for UK businesses. Despite the ongoing rollout of full fibre FTTP, millions of business premises remain on FTTC connections. Understanding what speeds you should realistically expect from FTTC, and what factors influence them, is essential for setting appropriate expectations and knowing when the time to upgrade has come.

How FTTC Works

FTTC is a hybrid technology. Fibre optic cable runs from the local telephone exchange to a green street cabinet, which you will have seen on pavements and verges. From the cabinet, the connection continues to your premises over the existing copper telephone wire — the same pair of copper wires that has connected most UK buildings to the telephone network for decades.

The fibre section delivers high bandwidth efficiently. The copper section is the bottleneck. Copper wire degrades signal quality over distance, which is why FTTC speeds vary so much between premises served by the same cabinet.

FTTC Speed Ranges by Distance

The distance from your premises to the street cabinet — the copper run — is the primary determinant of your FTTC speed:

• Under 100m from cabinet: Download 76–80Mbps, Upload 18–20Mbps
• 100–300m from cabinet: Download 60–76Mbps, Upload 15–19Mbps
• 300–500m from cabinet: Download 45–65Mbps, Upload 12–17Mbps
• 500m–1km from cabinet: Download 25–50Mbps, Upload 8–13Mbps
• Over 1km from cabinet: Download under 25Mbps, Upload under 8Mbps. At this distance, FTTC performance is increasingly poor and alternatives should be considered.

These figures assume a quality copper pair in good condition. In older buildings, internal wiring faults, poor quality extensions, or corroded connections can reduce speeds below even these estimates.

FTTC Upload Speeds: The Asymmetry Problem

A frequently overlooked characteristic of FTTC is its asymmetry. The technology allocates significantly more bandwidth to download than upload. For residential users downloading video content, this is acceptable. For businesses, upload speeds matter considerably:

• VoIP calls consume roughly equal bandwidth in both directions
• Cloud backup and file sync (OneDrive, SharePoint, Google Drive) require consistent upload bandwidth
• Video conferencing (Teams, Zoom) uses upload for your outgoing video and audio
• Sending large files to clients or suppliers is governed by upload speed

A typical FTTC connection with 80Mbps download and 20Mbps upload is manageable for small teams. For businesses with 20+ staff making simultaneous VoIP calls and running cloud applications, the upload limitation becomes a real operational constraint.

FTTC vs FTTP: The Speed Difference

FTTP (full fibre to the premises) removes the copper last-mile entirely. Fibre runs all the way to your building, delivering speeds that are not limited by line length and that remain consistent regardless of how many other businesses are using their connections simultaneously. FTTP products for businesses start at 150Mbps download and go up to 1Gbps or higher, with meaningfully better upload speeds than FTTC.

The practical implication: if your premises has FTTP available, upgrading is almost always worthwhile compared to FTTC — the speed and consistency improvement is substantial and the price difference is often modest.

Factors That Can Reduce Your FTTC Speed Below the Estimate

• Line quality: Old or damaged copper pairs carry less bandwidth than new ones
• Internal wiring: Old in-building telephone wiring can degrade performance significantly. A microfilter or filtered faceplate on the master socket can help in some cases
• Cabinet contention: At peak times, heavy use of the cabinet by nearby customers can reduce speeds marginally
• Router placement and Wi-Fi: Wireless connections to the router add another variable. Wired connections always outperform Wi-Fi on FTTC

When to Upgrade from FTTC

FTTC remains adequate for small offices with modest cloud requirements — typically up to 10–15 staff depending on workload. Signs that your business is ready to upgrade:

• VoIP call quality is inconsistent, particularly during busy periods
• Teams or Zoom calls are regularly choppy or dropping
• Staff report slowdowns during mid-morning or early afternoon when usage peaks
• Cloud application performance is noticeably slower than expected
• You have taken on more staff and bandwidth per person has become tight

AMVIA can assess your current FTTC performance, model your team's bandwidth requirements and advise on whether FTTP, bonded FTTC or a leased line is the right next step.