Major shift in government evaluation as Magenta Book is updated

The Evaluation Task Force has released the 2026 update to the Magenta Book, the government’s central guidance on evaluation. As the most significant revision in government evaluation standards since 2020, it marks a major milestone for evidence-based policymaking.

The 2026 update to the Magenta Book represents the most significant shift in government evaluation standards since 2020, moving the needle from “measuring what happened” to “learning how to improve in real-time.”

Led by the Evaluation Task Force (ETF), the update to Magenta Book, the UK government’s central guidance on evaluation, is a significant milestone for evidence-based policymaking in the UK.

For every civil servant, regardless of your role, adopting the principles of the Magenta Book is crucial for ensuring that government is driven by rigorous evidence, guaranteeing that taxpayer money is spent effectively. 

This update ensures that the guidance reflects the advances in evaluation practice since the previous 2020 version. The revised Magenta Book introduces several new and significantly expanded areas of focus to support high-quality evaluation across government. This includes: