Well-managed mine reconciliation processes provide the foundation of resource and reserve governance, as well as facilitating problem solving and continuous improvement. However, due to the complexity of the reconciliation chain, isolating the root cause(s) during periods of poor reconciliation can be challenging. As a consequence, failure to deliver to budget expectations is often conflated with poor resource model performance, despite resource performance being only one of several contributors to delivering on budget expectations. Permitting, mine planning, compliance to plan, resource model performance, ore extraction performance (dilution and ore loss), stockpile management, and mill throughput and recovery, all impact mine plan outcomes. In response to these challenges, OceanaGold has developed an integrated mine chain reconciliation system to assist each of its operations in tracking production performance across the mine chain from: compliance to mine plan –> resource/reserve model performance –> extraction efficiency –> net stockpile transaction –> Mine to Mill feed –> received at mill –> metal produced/recovery. The system is based on performance factors documented by the late Harry Parker (Parker, 2011) and uses waterfall charts to summarise performance across the mine chain. Interactive dashboards and tables allow a visual and more detailed technical analysis. The mine chain reconciliation (MCR) analysis approach has proven effective at identifying the link (or links) in the mining chain that are contributing to poor performance, avoiding misdirected, time consuming investigations, and preventing reactive management, particularly to short-term reconciliation disparities that reflect normal operational variability rather than underlying model performance issues. Initially piloted as an Excel-based process, OceanaGold’s MCR has now been migrated to an interactive SharePoint platform accessible to site personnel, technical centres, and senior management. Establishing and maintaining good reconciliation processes, reporting processes, and communications has resulted in improved teamwork, focus, and cultural change across the business. The recent introduction of structured quarterly reconciliation meetings which are formally minuted, has increased transparency and strengthened internal controls processes. Although OceanaGold’s operations comprise both open pit (OP) and underground (UG) mines, this paper mainly concentrates on UG reconciliation processes. OP reconciliation methodologies are already well established in industry practice and comprehensively documented across numerous publications (ie Morley and Arvidson, 2017). This paper presents operational case studies using the OceanaGold Corporation’s (OceanaGold) reconciliation process to identify some common reconciliation challenges. This paper is not intended as a comprehensive overview of mine reconciliation.