Adoption of legal technology within law firms has seen a significant increase in recent years with the current necessity for seemingly indefinite remote working only adding to the need for technology solutions to keep legal workflows running. In light of this, legal technology purchases will undoubtedly see a further increase and a well conducted proof of value is crucial to making the right investment decision. This article is based on a talk given by Eleanor White at the BIALL Knowledge Management SIG in November 2018. It establishes the difference between a proof of concept and proof of value and elaborates on some key principles to consider during each phase of the latter. From the preparation and planning through to the running of the evaluation and the resulting decision-making process, this article addresses how to get the most out of the proof of value opportunity.