The ‘big 4’ ISPs’ combined revenue remained in decline in Q4 2024 at -0.4%, partly due to a BT accounting quirk but mainly due to altnets gaining share

ARPU growth of 2% is roughly compensating for subscriber declines of 2%, but this ARPU growth is likely to weaken in 2025 as various boosts drop out

A recovery will come as the altnets slow in H2 2025 (if not before) due to their restrained expansion, which cannot come soon enough for the big ISPs

CityFibre has reported positive EBITDA in 2024, albeit at a slim 4% margin, and still needs further scale—and to successfully onboard its new wholesale customer Sky—to drive decent investment returns.

CityFibre’s organic build rate is dropping sharply as it (sensibly) looks set to rely on consolidation to achieve the required scale, with its organic build focused on Project Gigabit areas.

CityFibre remains well-positioned for consolidation, but this may take some time yet, with the altnet sector set to slow organic progress anyway in the interim.

BT had a solid-but-mixed Q3, with revenue growth slightly weaker than expected, EBITDA growth slightly stronger, and subscriber net adds a touch weak across broadband, mobile and Openreach 

The outlook is buoyed by a likely altnet slowdown at some point in FY26, with this set to help subscriber numbers at Consumer/Openreach and pricing at Consumer

The main cloud is the potential effect of a merged Vodafone-Three challenging BT/EE for best network and boosting MVNOs, a challenge we feel is real but manageable for BT

The mid-sized UK altnets Zzoomm and FullFibre have agreed to merge, in what looks like an all-share merger of (nearly) equals, both of whom have been struggling to raise finance.

Why did they pick each other rather than the larger CityFibre/Netomnia/nexfibre options? Valuation may have been the key factor, but it has left them still vulnerably low scale with further consolidation necessary.

Much more consolidation is required for the sector to be sustainable in our view, and further financial distress may be required for realistic valuations to emerge.

Starlink has unveiled its plans for its next-generation satellites, boasting dramatically more capacity than was anticipated, as it aims to bring gigabit speeds to its broadband users.

This rapid growth in capacity poses the risk of a more commercially aggressive Starlink. While this will amplify its impact on the broadband market, it remains a somewhat niche consumer proposition but with additional B2B appeal.

Amazon's Kuiper is gearing up to begin launching its own satellites. While its target of introducing service later this year is likely to slip, Kuiper will bring an important peer competitor to Starlink, and will be the first time that Amazon's retail and marketing heft enters the UK connectivity market.

Market revenue dipped into marginal decline in Q3, as both ARPU and sub growth weakened, both partly driven by the continued altnet onslaught
 

Backbook pricing effects will be of marginal help in the short term, but new customer pricing competition is still fierce, and households are still cash-strapped
 

In the longer term, pressure from the altnets should wane substantially as their roll-outs slow and they consolidate towards a wholesale model (or fail)

BT Group was hit by an unexpected slowdown in Global/Portfolio non-UK corporate revenue in Q2, with this impacting quarterly and full year expected revenue by 2ppts.

EBITDA, cashflow and all other operational metrics were steady or improving, with Openreach particularly strong, and without the non-UK impact it would have been a solidly good if unspectacular quarter.

The fibre-driven cashflow turnaround plan is therefore still very much on track, with the expected altnet slowdown/consolidation an added potential bonus, and the Vodafone-H3G merger a manageable challenge.

The UK altnets collectively lost over £1bn in 2023, with most metrics unrealistically distant from what they need to be for a sustainable model, particularly the smaller retail-focused operators.

Consolidation is essential for survival, and CityFibre at least has a reasonable case for long term sustainability with a wholesale model and Sky as a customer, and looks the most viable altnet consolidator in our view, with VMO2/nexfibre able to pick up the pieces should the sector fail.

A lack of long-term viability and related financing difficulties will dramatically slow network roll-out, reducing the altnet pressure on the rest of the sector even if consolidation improves penetration levels.

In the next fixed line regulatory review—TAR 2026—Ofcom is likely to maintain light regulation on Openreach’s pricing levels, while also maintaining strict restrictions on its pricing structures, which both help altnets. 

On other matters, none of the interested parties (Openreach/altnets/ISPs) look like getting exactly what they want, but by and large the industry will likely get what it needs—regulatory stability with a broadly pro-investment slant.

The next TAR in 2031 is likely to be more dramatic, but by our estimates, even a full return to cost-based charging will not result in significant wholesale price cuts, which is likely to be a relief to longer term investors in BT and the altnets alike.

CityFibre has announced a deal to supply the second largest UK ISP Sky with wholesale broadband services, doubling its addressable target market at a stroke, in a blow to Openreach.

This may be just a foot in the door for CityFibre, but it is a critical one, and puts it firmly in the driving seat for altnet consolidation. There are also positives for VMO2 and other altnets hopeful of an eventual wholesale deal with Sky, and for retail ISPs now that the altnet sector is pitching towards wholesale away from retail.

While this is obviously bad news for Openreach, we see it more as an absence of a potential positive than something that might actually worsen current trends, and there are mitigating positives for the wider BT Group.