Companies develop and integrate carbon scenario analysis, internal carbon pricing, and emissions reduction targets to aid in decision-making, forecasting, and managing climate change risks and opportunities. However, for these strategies to be effective, they require accurate and reliable carbon information and planning. Companies have significant discretion in developing, implementing, and applying these strategies, which raises stakeholder credibility concerns. Stakeholders also have uncertainties about the accuracy, reliability, and robustness of carbon information and the systems and processes used by companies for these strategies, known as internal carbon uncertainty. Meanwhile, carbon assurance, which can reduce internal carbon uncertainty and improve credibility, is voluntary. Utilising a multi-theoretical framework of stakeholder, resource dependence, and signalling theories, this study argues that companies will address stakeholder concerns regarding their carbon strategies, including carbon uncertainty and credibility concerns, by adopting carbon assurance. The study also found that the results remain consistent when different emissions are assured. While the engagement with policymakers, the value chain, and the occurrence of COVID-19 moderate the relationship between carbon strategies and assurance adoption. The findings demonstrate that carbon assurance is critical in improving carbon strategies and addressing stakeholder concerns.