Council Tax Valuation Operating System (CT VOS) Evaluation
Published 20 January 2026
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Project Overview
Council Tax Valuation Operating System (CT VOS) is a major digital transformation initiative for the Valuation Office Agency (VOA). CT VOS, formerly known as the Council Tax element of the VOA’s Business Systems Transformation (BST), is designed to re-engineer core business processes and replace legacy IT platforms with a fully integrated system. This transformation aims to introduce new geospatial tools, a customer portal for local authorities, automated casework allocation, and centralised content management. The programme aims to make the VOA more flexible, efficient, and resilient, supporting the delivery of trusted valuations and underpinning approximately £45 billion in annual Council Tax revenue. By consolidating multiple systems into a single platform, CT VOS will enable consistent, rapid responses to customers and ensure the agency can meet statutory obligations.
Evaluation Design
The evaluation plan recommends undertaking a process and value for money evaluation of the CT VOS. The impact is largely expected to be internal to the VOA. The process evaluation will retrospectively investigate whether the programme was delivered as intended, what worked well, and what could be improved, drawing on document reviews, surveys, focus groups, interviews, and internal performance indicators. The evaluation will draw on both quantitative performance metrics and qualitative insights with key indicators including delivery fidelity, communication, training, support, and adaptation. The value for money evaluation will examine whether expected benefits (such as operational efficiencies and IT system failure avoidance) are realised and how these compare to the costs incurred.
Next Steps
Following programme closure, a post-implementation review will take place after 6 months, with a full process evaluation scheduled for 12 months after the closure of the programme. Ongoing monitoring will continue to assess value for money and system performance, and findings will be published and shared to inform future projects and continuous improvement within the agency.