An Open Local Digital Twin (LDT) relies on standards-based interfaces and components to ensure replicability, reuse, and future maintainability. This chapter provides an overview of relevant LDT standards in different Pivotal Points of Interoperability (PPI), in the LDT core components and the data, modelling, and visualisation domains. The chapter aims to provide a neutral overview of useful standards and components at different levels of standardisation, such as encoding standards, syntax and semantic-related standards, and, if available, standards about business interactions. Based on the LDT architecture building blocks (BB), the current maturity level and relation with the Minimal Interoperability Mechanisms (MIMs) concept is scrutinised. This analysis shows a variety of maturity and existing standardisation gaps, mainly related to the interactivity of LDT services and the cooperation between domain-specific simulation models. However, the LDT can benefit from existing standards in the data and visualisation domains, as well as the further development of common ontologies for domain-overarching service customisation support. Cross-domain digital twin cases and scenarios will contribute to more cost-efficient construction of policy-supporting, predictive LDTs.