- The Real-Time Gross Settlement (RTGS) is a core part of the UK’s financial infrastructure, and the Bank of England successfully launched the renewed system in April 2025 at a cost of £431 million
- Every day, on average, £790 billion worth of transactions are processed and settled through the RTGS system
- The National Audit Office (NAO) recommends the Bank prioritises maintaining and enhancing the system to maximise long-term value, and applies lessons learned from the renewal to its other digital and business transformation projects
The Bank of England successfully navigated complex risks and interdependencies to deliver its Real-Time Gross Settlement (RTGS) renewal programme, incorporating innovation and best practice in managing this digital transformation, says the NAO.
The RTGS is a critical financial infrastructure that underpins the stability of the UK’s payment systems, including CHAPS, the UK’s high-value payment system and retail payment systems like Bacs.
In its latest value for money report, the NAO examined how the Bank managed the RTGS renewal programme to achieve a new system resilient to future developments and risks.
Overall, the independent public spending watchdog found the Bank’s management of the programme demonstrated value for money, and good practice in digital transformation, offering lessons for other government projects and the Bank’s wider project management.
The delivery
Delivered over nine years from initial announcement (January 2016) to implementation (April 2025), the £431 million programme was completed despite several challenges.
The Bank invested significant resources upfront in planning and procurement before moving on with design and implementation. During the planning stages the Bank made three key decisions to build rather than buy an RTGS, appoint an external delivery partner, and implement a new technology approach.
The Bank’s procurement approach enabled it to refine designs with three suppliers before signing contracts and featured an innovative ‘competed design’ process where bidders created a simplified payment system to demonstrate their technical capability and responsiveness to customer needs. Accenture were chosen as the main delivery partner.
Programme staffing peaked at over 450 staff in 2022 and 2023, with active planning and managing of resourcing to make use of internal payments and technical specialists, alongside external expertise. To manage potential impacts on other areas in the Bank, it regularly reviewed dependencies and engaged with other projects across the Bank’s portfolio. It also fostered a transparent, open culture with strong leadership and collaborative working between business and technical areas.
All of these are examples of where the Bank’s approach to delivery demonstrated good practice.
Mitigating challenges
To manage risk effectively, the Bank adopted a ‘three lines of defence’ model, through combining internal assurance, oversight from the risk directorate and internal audit, in addition to commissioning external assurance.
Four major replans addressed challenges which included a technology platform change; an external shock caused when the European Central Bank moved its timetable for a major upgrade programme which created too much simultaneous change for users; and technical issues requiring additional testing to resolve.
These replans delayed launch by around 18 months, which the NAO reported as being at the lower end of delays. In government digital change programmes NAO has observed delays from one to eight years.
The most significant challenge was the platform change during the first replan as it required moving from a shared Bank technology platform to a programme-specific one. This led to a full reset, governance changes, and removal of some future enhancements.
The programme’s estimated cost rose to £431 million, 15% above the original £375 million budget set in the 2020 business case, which included only 11% contingency – lower than industry norms. Around £23 million of the increase stemmed from the change in the ECB migration date.
The NAO concluded that given the programme’s size, complexity, and inherent risks, the cost increase is reasonable.
Next steps
With the new RTGS in place, the Bank is improving functionality over the next two to three years and will need to set long-term priorities to maintain and improve the system. The NAO recommends the Bank:
- Applies lessons learned to its other digital and business transformation projects.
- Sets clear plans for ongoing investment and resourcing to keep the RTGS and supporting services up to date.
- Understands and manages the impact of higher levels of change on RTGS users.
- Assesses how effective its interventions to widen access and reduce barriers to the RTGS are, to make sure it puts the best mix in place.
“The RTGS is part of critical national infrastructure, providing a vital foundation to the UK’s payments system and contributing to the resilience and stability of the UK economy.
“The Bank placed a high priority on the RTGS renewal programme combined with a low tolerance for failure. Its careful planning and well-managed delivery approach ensured value for money and set an example of good practice and innovation for future digital change projects.”
Gareth Davies, head of the NAO
Read the full report
Bank of England’s Real-Time Gross Settlement System Renewal Programme