G.Fast for Business: Speed, Cost and Availability

G.Fast occupies a specific position in the UK broadband hierarchy: faster than FTTC but less capable than FTTP, and available only in limited areas. For businesses in G.Fast coverage zones where full fibre has not yet arrived, it can provide a meaningful speed boost at a relatively modest cost. Understanding how the technology performs in practice — and what the caveats are — helps businesses make an informed decision about whether to pursue it or wait for FTTP.

G.Fast Speeds: What Businesses Actually Experience

G.Fast speeds depend primarily on the length of the copper run from the distribution point unit (DPU) to your premises. Unlike FTTC, where street cabinets can be hundreds of metres away, G.Fast DPUs are placed much closer — typically within 50–200 metres of the building they serve.

Real-world speeds on G.Fast from Openreach:

• Under 100m from DPU: Download 250–330Mbps, Upload 40–50Mbps
• 100–200m from DPU: Download 150–250Mbps, Upload 30–40Mbps
• 200–350m from DPU: Download 80–150Mbps, Upload 20–30Mbps

Beyond around 350–400 metres, G.Fast performance degrades towards FTTC levels and the advantage is diminished. In practice, Openreach only activates G.Fast connections where the DPU is close enough to deliver meaningful improvement.

Upload Speeds: The Key Business Consideration

G.Fast's upload speeds — while much better than FTTC's — remain asymmetric. The maximum upload of around 50Mbps is sufficient for most SME workloads: Teams calls, cloud backup, hosted VoIP for dozens of users. However, for businesses with significant upload demands — video production, large file transfers, hosting services — the symmetric upload of a leased line (100Mbps+ up and down) may be more appropriate.

How G.Fast Is Priced

G.Fast business broadband pricing sits in a similar range to FTTP products of equivalent speeds. For businesses that can access G.Fast, indicative pricing on 24-month contracts:

• G.Fast 100–150Mbps: approximately £40–£55/month
• G.Fast 200–330Mbps: approximately £50–£70/month

These prices are broadly comparable to FTTP at similar speeds. Given that FTTP offers better long-term performance and upload symmetry, the pricing overlap makes G.Fast less compelling where FTTP is also available. G.Fast is primarily relevant where FTTP has not yet been deployed.

Where Is G.Fast Available?

G.Fast is available only where Openreach has deployed distribution point units in the relevant cable run. The rollout has been limited and geographically uneven. Checking your specific postcode via BT's availability tool or AMVIA's multi-network availability check will confirm whether G.Fast is an option at your address.

Key characteristics of G.Fast coverage:

• Available in some urban and suburban areas that had G.Fast DPUs installed as part of Openreach's G.Fast programme
• Not available where standard FTTC cabinets have not been upgraded with G.Fast DPU infrastructure
• In some areas, G.Fast and FTTP may both be available, making FTTP the clear choice
• In areas where Openreach has not deployed G.Fast, FTTC remains the only copper-based option

G.Fast vs Leased Lines for Business

G.Fast is a shared-access broadband technology — it is not dedicated bandwidth. During peak periods, performance can be affected by the number of businesses and residents using the network. A leased line provides guaranteed, uncontended bandwidth regardless of what others on the network are doing.

For businesses where internet reliability and consistent performance are commercially important, a leased line remains the more appropriate solution. G.Fast suits businesses with moderate bandwidth needs (up to around 50 staff depending on workload) where the cost of a leased line cannot be justified.

Should You Choose G.Fast?

Consider G.Fast if:

• It is available at your address and FTTP is not yet deployed
• Your current FTTC speeds are inadequate for your team's needs
• You need a better connection than FTTC can provide but a leased line is not justifiable
• You are willing to accept some performance variability in exchange for lower cost

Wait for FTTP instead if:

• Openreach or CityFibre FTTP is planned for your area within 12–18 months
• Your current FTTC is just about adequate and changing providers now would be disruptive
• You want future-proof infrastructure that will not need to be replaced again