Interoperability frameworks are a key enabler for GovTech, the World Bank's whole-of-government approach to public sector modernization, as they reduce system boundaries between government agencies by setting standards and guidelines across government systems to allow for seamless exchange of information and communication between systems. But governments may face several challenges when setting up and implementing interoperability frameworks, related to a mix of technical, semantic, legal, organizational, and cultural factors. This How-to Note provides advice on what interoperability in the public sector is, why it is needed and how it can be implemented with various examples and a whole-of-government approach to interoperability taking into account both digital and nondigital aspects is of the essence.