The Regulation on harmonised rules on fair access to and use of data (Data Act) entered into force on 11 January 2024 and applies from 12 September 2025, establishing a cross-sectoral framework that clarifies who can use what data and under which conditions. It ensures users of connected products and related services can access and use the data they co-generate, enables fair business-to-business sharing when required by law under fair, reasonable and non-discriminatory terms, and protects businesses (particularly SMEs) against unfair contractual terms. It creates an exceptional-need channel for business-to-government access to data for defined public-interest purposes, with strict safeguards. It removes obstacles to switching between data-processing (cloud/edge) services and abolishes switching and data-egress charges from 12 January 2027, supporting interoperability and reducing lock-in. It introduces safeguards against unlawful third-country governmental access to non-personal data and advances interoperability requirements (including smart contracts) to allow data to flow within and between data spaces. Member States must designate competent authorities, where relevant a data coordinator as a one-stop shop, and penalties must be effective, proportionate and dissuasive.