Sharing public sector data can improve public services, facilitate research and innovation, and inform policymaking. However, public sector bodies face challenges when sharing data, both within the public sector and externally. These include cultural and skills barriers, poor data quality, and lack of public trust. Sharing public sector data also raises security and privacy concerns. This POSTnote looks at how public sector data is shared in the UK, discussing the requirements for effective data sharing and the associated benefits, risks, and barriers.