UK data centres: the AI boom's engine rooms barely make money

Britain is in the middle of the biggest data-centre construction boom in its history — and you can barely see it in the profit column. Among the 193 UK data-processing and hosting companies that publish a full profit-and-loss, booking £9.38bn of combined turnover, the businesses that actually run servers for a living are the weakest numbers on the page: Rackspace’s top line fell 10% with headcount down 14%, NTT’s UK data-centre company lost £26.2M, and Global Switch’s two London estate companies lost nearly £80M between them. Add up the eleven recognisable data-centre and hosting rows in the category and they book close to £890M of revenue and roughly £110M of combined losses. The money here belongs to companies that sell what lives on the servers — a derivatives record-keeper at a 65.6% margin, vehicle-history data at 24–26%, a quietly enormous content-delivery network clearing £47.5M — while the boom itself shows up not as profit but as hiring: Stack Infrastructure’s EMEA management company — the entity staffing the STACK build-out — more than doubled its headcount from 23 to 49. Figures are approximate — verify against a company’s own accounts before relying on any single number.

Read the category first

Three things change how you read every number below.

Most of this category isn’t hosting. “Data processing and hosting” is where Britain’s data businesses of every description end up: research houses (Gartner UK, GlobalData), a clinical-trials giant (ICON Clinical), sports-data feeds (Genius Sports), a contact-centre outsourcer (Capita Customer Management), payments and consumer-credit apps, and the captive technology arms of much bigger groups — Hillside (Technology) is the engineering side of the bet365 betting group, and PwC IT Services exists to serve its own network. The genuine data-centre and hosting operators are a minority of the register they nominally define.

The estate itself mostly lives elsewhere. The companies running most of Britain’s server halls are registered under neighbouring categories, so they don’t appear in the tables below: Equinix’s main UK company books £657.8M (£26.6M profit), Telehouse £314.8M with £88.7M of profit, Virtus about £486M, Vantage £154.3M, Pulsant £100.2M — and Amazon’s UK data-centre company puts £944.9M through at a 1.3% margin, priced by its parent to do exactly that. This map is a window on the industry’s economics, not a census of its buildings.

The vendor arms’ margins are arithmetic, not performance. The UK companies of American software and cloud vendors — Snowflake (£133.6M at a 2% margin), Workday, Rubrik (a 27% margin), Vast Data (a loss the size of its entire revenue) — earn whatever the group’s intercompany agreement says they earn. They are flagged in the tables and excluded from every competitive read.

The giants: mostly not hosting

…and 181 more. Factiva’s £82.2M of profit flows through 39 employees — a licensing structure, not an operating margin. Hillside’s revenue is billed to its own group. Capita Customer Management is the register’s biggest loss and its hardest contraction: revenue down 29%, staff down 36%.

The table is the first finding in itself: of the twelve biggest companies in Britain’s hosting category, exactly one — Rackspace — hosts things for a living, and it is the one with a shrinking top line. One caveat on its bottom line: the UK entity is remunerated cost-plus by its Swiss affiliate, so near-zero profit is by design — the story is the −10% revenue and −14% headcount, not the margin. Kyndryl, the old IBM infrastructure-services business, is the closest thing to a giant that actually runs other people’s IT estates, and it holds a 2% margin on £853.2M while revenue drifts down 4%.

The engine rooms: what running the boxes actually earns

Strip the category down to the companies that genuinely operate data centres or sell hosting, and the boom’s paradox is on one page:

Together: close to £890M of revenue, roughly £110M of combined losses — and note the composition: roughly £93M of that revenue is the two management companies’ intra-group billing, and Rackspace’s £354.8M is substantially cost-plus billing to its own group; strip the management companies out and the picture is unchanged (≈£794M of revenue, ≈£115M of losses). The pattern isn’t mismanagement — it’s the model. Colocation is a property business wearing a technology badge: the revenue is rent for space, power and cooling, and the profit is consumed below the operating line by depreciation on nine-figure builds and the financing that paid for them. Global Switch’s estate companies book the kind of losses a heavily geared property vehicle books, not a measure of empty racks. Managed hosting — Rackspace, iomart, Navisite — is the opposite problem: a labour business squeezed between the hyperscale clouds and its own legacy contracts, where the healthiest steady number is Kinsta’s 7% margin (Navisite’s 9.6% arrives alongside a +47% revenue jump that looks like post-acquisition reorganisation rather than organic hosting).

And this is where the boom actually is — but read it as hiring, not revenue. The two fastest-growing rows are both intra-group management companies: Stack Infrastructure, which bills the STACK group’s operating companies for supporting the EMEA build-out, took headcount from 23 to 49; VDC UK Management, Vantage Data Centers’ EMEA management company, hired 39% more staff. Their headcount is real evidence of the build-out; their +69% and +51% “revenue” is affiliate billing that mechanically follows the payroll, not market wins. The build-out itself pays construction firms, lenders and (eventually) landlords before it pays anyone’s P&L here. For what the destination looks like, look outside the category: Telehouse, running mature campuses it owns in Docklands, Paris and Frankfurt, converts £314.8M into £88.7M — a 28% margin carried by a legacy asset base with far lighter depreciation than the new builds (the group is still spending: £232.6M of capex last year).

Most of these entity accounts also sit inside global platforms (Colt, NTT, Stack, VDC/Vantage, Global Switch), so their UK margins are shaped by intercompany leases and recharges — compare trajectories, not margins, across this table.

The quiet money: the data pays, the centre doesn’t

The reliably profitable companies in the category don’t run infrastructure — they sell information that happens to live on it, on subscription and fee models where the capital cost is someone else’s problem:

DTCC’s 65.6% flows through two employees — a fee-collecting entity whose costs sit elsewhere in its group; treat it as a structure, not a benchmark. A domain registrar in the set shows £104.9M of profit on £53.4M of revenue — dividends from group companies, not trading — and a holding company shows a 100% margin for the same reason; both are excluded here. Datacamp and DTCC file their accounts in US dollars; the sterling figures shown are converted at roughly $1.34/£.

The standout is Datacamp, the London company behind one of the world’s larger content-delivery networks: £130.2M of revenue, £47.5M of profit, growing 25% a year, and almost nobody in Britain has heard of it. It is the exception that proves the rule — the one genuinely infrastructure-flavoured business making serious money, and it makes that money by renting capacity across other people’s data centres rather than building its own.

The shape of the market

Only 24% of the under-£1M band makes money — small hosting is a brutal place to be when the hyperscale clouds set the floor price of a server. Even at the top, three in ten of the £100M+ companies are loss-making, which almost no other category we’ve mapped shows; that’s the colocation landlords and the loss-tolerant vendor arms pulling the big end down.

Growth, read with care

Most of this table is not what it looks like. Clsq’s +1,422% is a restart from a near-idle base. Vast Data and Rubrik are US vendors’ UK arms — one showing a loss the size of its revenue, the other a 27% margin, and both numbers are group arithmetic rather than trading. Consilio’s £126.7M loss on £126.0M of revenue is a group-structure event, not a business halving in a year. Zilch is a consumer-credit app that merely lives in this category. Stack (+113% staff) and VDC UK Management (+39%) are the boom’s staffing arms — both intra-group management companies whose revenue is affiliate billing, so read their headcount as the signal and their top lines as recharges. That leaves WeTransfer’s UK company as the table’s cleanest grower — a young entity filling out into real scale with real hiring.

Market structure and vintage

The top five hold just 27.6% of the £9.38bn — one of the least concentrated categories we’ve mapped, and that is itself diagnostic: this isn’t one market with dominant players, it’s a dozen unrelated businesses filed under the same label. Ownership skews heavily corporate (117 of 193, against 56 individually owned), consistent with a register full of group subsidiaries; 22 companies carry the Holdings/Bidco naming fingerprint of private-equity structuring.

The vintage chart shows two distinct generations: 56 companies from the 2000s — the broadband-era hosting and data businesses — and a second wave of 59 incorporated since 2016, the cloud and AI cohort that includes almost every loss-making high-growth row above. Only 16 companies pre-date 1990; nobody’s grandfather ran a data centre.

What the map shows

1. The boom is nearly invisible where you’d look for it. Britain’s marquee data-centre operators — Equinix (£657.8M), Telehouse (£314.8M), Virtus (~£486M), Vantage, Pulsant, Amazon’s £944.9M build-out arm — are all registered outside the hosting category. What’s inside is a partial window, and it should be read as one.
2. Running the boxes doesn’t pay — yet. The eleven data-centre and hosting rows in the category book close to £890M of revenue and lose roughly £110M between them (≈£794M and ≈£115M excluding the two intra-group management companies); depreciation and financing eat colocation’s P&L, and the hyperscale clouds squeeze managed hosting’s.
3. The boom shows up as hiring, not profit. Stack’s and Vantage’s EMEA management companies — the entities staffing the build-out — more than doubled and grew headcount 39% respectively; their revenue lines are intra-group recharges that follow the payroll. Construction firms and lenders get paid first; Telehouse’s 28% margin on mature, owned campuses is what the survivors are building towards.
4. The money is in the data, not the centre. A derivatives record-keeper (65.6%), vehicle-history data (24–26%), pharma intelligence (31%) and a near-anonymous £130M CDN making £47.5M — subscription and fee businesses whose capital costs are someone else’s — hold the category’s real margins.
5. Vendor arms’ numbers are arithmetic. Snowflake’s 2%, Rubrik’s 27% and Vast Data’s −100% margins are intercompany pricing, not performance; rank none of them.
6. Small hosting is a graveyard. Only 24% of the sub-£1M tier makes money — the worst small-company profitability we’ve mapped — because the price of a server is set by companies that build their own power stations.

Methodology and caveats

This covers only the 193 UK data-processing and hosting companies that publish a full profit-and-loss, out of a register of around 600 — most of the rest file small-company accounts with no revenue figures and are invisible here. The category is a mixed bag by construction: research, outsourcing, payments and captive technology arms sit alongside genuine hosts, and most of Britain’s large colocation operators are registered under neighbouring categories, so the in-category totals understate the data-centre industry itself. Margins are not comparable across the category’s different models — colocation landlords, managed hosts, fee-based data businesses, licensing entities and cost-plus vendor arms — and several profit figures (Factiva, DTCC, the registrar with dividends above revenue) are group structures rather than trading results; the large losses at property-heavy operators typically include depreciation, financing and valuation movements rather than operating shortfalls. Two of the engine-room rows (Stack Infrastructure EMEA, VDC UK Management) are intra-group management companies whose revenue is affiliate billing, and Rackspace’s UK entity is remunerated cost-plus by its Swiss affiliate — their margins are administered, not market outcomes. Companies filing in US dollars (DTCC Derivatives Repository, Datacamp, Team Internet Group) are shown converted to sterling at roughly $1.34/£, so their filed accounts state different dollar figures. Where a group files through several entities (Global Switch’s two estate companies, Genius Sports’ two companies, a listed domains group and its subsidiaries), each entity is shown as filed and group totals may differ. Each row uses the latest accounts available when the data was assembled, and newer accounts may since have been published. Figures are approximate and business-type labels are directional. This is analysis, not financial advice — verify any specific figure against the company’s own accounts.