In the face of the ongoing biodiversity crisis, questions are arising regarding the success, or lack thereof, of biodiversity offset schemes, where biodiversity losses from human development are compensated by producing equitable gains elsewhere. The overarching goal of offsetting is to deliver no net loss (NNL) of biodiversity. Assessing whether offsetting does indeed deliver NNL is, however, challenging because of a lack of clear and reliable information about offset schemes. Here we consider barriers in tracking NNL outcomes, outline criteria of public offset registers to enable accessible and credible reporting of NNL, and show how existing registers fail to satisfy those criteria. The lack of accessibility and transparency in existing registers represents a fundamental gap between NNL targets and a valid tracking system, which challenges the impetus to enact the transformative changes needed to reverse biodiversity decline.