£23.2bn is what Britain had spent on building its Dreadnought-class submarines by March 2026, according to the Ministry of Defence’s annual report to Parliament on the Defence Nuclear Enterprise. The program will deliver four boats against a build estimate of £41bn. The report says the first, HMS Dreadnought, is due to be ready to enter service with the Royal Navy in the early 2030s.
The Defence Nuclear Enterprise 2026 Annual Update to Parliament was published on gov.uk on Sept. 15, 2026. It is the 13th report in a series of updates the MoD first committed to in 2011, and it covers progress since the previous update in May 2025.
The figures are in the Dreadnought section of the 2026 annual update: “Spend in the year to March 2026 was £3bn, bringing the total spend to £23.2bn.” The same section sets that against the program’s cost ceiling: “The previous government estimate was the Dreadnought build programme would likely cost £41bn (£31bn plus £10bn contingency).”
The MoD’s position is that the job is still inside that figure. “The current forecast to completion remains within this envelope,” the report says. It also says the program “continues to face significant pressures and associated risks given the complexity of this mega project and the wider economic environment.”
Four boats to replace the Vanguard class
The report sets out the program’s scope plainly: “The Dreadnought Programme will deliver the four Dreadnought Class submarines to replace the current Vanguard Class.” Per the same document, the new boats “will carry Trident II D5 missiles armed with sovereign UK nuclear warheads,” and the Vanguard boats they succeed have been “protecting the UK and our allies continuously since 1969.”
The submarines are being built in one yard. “All UK submarines are manufactured by BAE Systems in Barrow-in-Furness,” the report states, adding that BAE Systems, Babcock and Rolls-Royce Submarines Ltd are among the organizations that “maintain teams in Barrow” for the Dreadnought and Astute build programs.
The last of the four is already under way. According to the MoD, the first steel cut for the fourth boat, HMS King George VI, took place in September 2025 at a ceremony in Barrow-in-Furness, “marking the beginning of construction.” BAE Systems’ account of the ceremony, dated Sept. 22, 2025, quoted Steve Timms, managing director of its Submarines business: “Cutting steel on the fourth Dreadnought submarine demonstrates the significant progress we’ve made on the programme.” BAE said the Dreadnought boats are “due to enter service from the early 2030s.”
£8.4bn for Delivery Phase 4
The next stage of the build has been funded. The report says Delivery Phase 4 for the Dreadnought build program was announced in July 2026 and describes it as an “£8.4bn investment” that “will support a supply chain encompassing hundreds of companies and tens of thousands of jobs across the country, from Barrow to Bristol.”
That phase, per the MoD, will see HMS Dreadnought complete her sea trials and be “ready to enter service with the Royal Navy in the early 2030s.” The shore side is moving in parallel: the report says the base at Devonport is being prepared for “the arrival of Dreadnought Class SSBNs and SSN-AUKUS Class SSNs throughout the 2030s and 2040s.”
£12bn across the enterprise
Dreadnought is one program inside a larger nuclear budget. The report says the Defence Nuclear Enterprise “spent £12bn in the financial year 2025/26” and “has a projected spend of over £100bn through UK suppliers over the next ten years.” It counts “over 47,000 jobs supported by the enterprise,” with demand “expected to rise to 65,000 by 2030.”
The same update lists other submarine milestones. HMS Agamemnon, the sixth Astute-class submarine, was commissioned at Barrow in September 2025, and the report says steel “will be cut on the first UK SSN-AUKUS submarine in 2027.”
For the Dreadnought boats, the MoD’s account stands at four boats in the program, the fourth in construction since September 2025, £23.2bn spent through March 2026, and the first boat due to be ready for Royal Navy service in the early 2030s.
Top image: Devonshire Dock Hall at BAE Systems’ Barrow-in-Furness shipyard, where Britain’s submarines are built, in July 2010. Image Credit: Stephen Middlemiss — CC BY-SA 2.0 / Wikimedia Commons
This article was produced with the assistance of AI and reviewed by Combat Rated editors prior to publication.