A note discussing how online platforms' dealings with consumers and business users are regulated. The note considers the impact of the Regulation on promoting fairness and transparency for business users of online intermediation services (Regulation (EU) 2018/0112) (known as the Platform to Business Regulation). It also looks at the changes the Enforcement and Modernisation Directive (Regulation (EU) 2019/2161) (also known as the Omnibus Directive) have made to the EU regime and upcoming changes to the UK and EU regimes. It contains key information for websites operating as marketplaces or other types of platform.