Microsoft Walks Away From Britain's Largest AI Data Centre

Microsoft has terminated its agreement to take capacity at Nscale's planned data centre in Loughton, Essex, Reuters reported on 18 October 2026, citing a Telegraph report published the same day. Microsoft was one of the two largest customers of the British cloud provider and was to be the anchor tenant at its first UK site. Microsoft declined a Reuters request for comment.

Nscale pledged £2bn last year to build the facility, which the BBC describes as the largest AI data centre in the UK and which is expected to create 250 permanent jobs when it opens. Microsoft had said it would fund a supercomputer at the site. Last month the company announced that some of the $30bn (£22bn) it is investing in the UK would pay for it.

The connection that slipped to the 2030s

The data centre was due to receive its power supply at the end of this year. Nscale has been told it will not arrive until the 2030s, the Telegraph reported first and the BBC confirmed on 18 October 2026. That is a delay measured in years, not quarters, on a site whose entire commercial case rests on energising racks before the hardware inside them is obsolete.

Nscale says it is not abandoning the project. A spokesperson told the BBC the company was exploring other ways to power the site.

The company also played down the damage to its relationship with its largest customer, telling the BBC that "this unfortunate London-wide grid issue has no impact on our other contracts" and that the relationship with Microsoft "remains strong and long-term". The two are still working together on projects in Norway, Portugal and the United States.

What the prospectus promised

The timing is awkward. Nscale filed for an initial public offering in the United States last month, and its prospectus names Microsoft and Anthropic as expected major customers, according to Reuters. The Nvidia-backed company has grown from $100 million to more than $103 billion in total contracted value in two and a half years, Reuters reported, and competes with CoreWeave, Nebius, Crusoe and Lambda. It has positioned itself as Britain's sovereign data centre provider.

Contracted value is a promise, not revenue, and this is the week the distinction acquired a face. An anchor tenant walking away from the flagship domestic site, weeks before a listing that lists that tenant, is the kind of detail institutional buyers read twice.

Nscale is the second AI infrastructure business in six weeks to have a public listing complicated by investor scepticism about debt-funded compute. As Parallax Nexus reported on 12 October, Firmus shelved a $5bn Sydney float and said it would raise privately instead. The common thread is not demand for AI capacity, which nobody disputes, but the gap between contracted demand and the physical plant needed to serve it.

The honest reading is that the binding constraint on British AI capacity has stopped being capital and started being interconnection. Nscale could raise the money and sign the tenant, and still could not get electrons to Loughton inside the decade. A grid queue is a slower problem to fix than a funding round, and it is not one a prospectus can solve.

What is not established is the reason for Microsoft's exit. Reuters was explicit that the Telegraph report did not specify why the company withdrew, Microsoft has said nothing on the record, and the grid delay is a plausible cause rather than a confirmed one. Nor has anyone disclosed what the terminated agreement was worth, or whether Microsoft owes anything on cancellation.