As the UK faces potentially significant legal and regulatory change resulting from the Brexit vote, there is a real opportunity for businesses to engage in joint lobbying on the shape of the UK exit. But in doing so, they need to keep an eye on competition law risks. On 23 June 2016, the UK voted to leave the European Union, triggering a period of uncertainty for businesses and the prospect of significant legal and regulatory changes. The coming months and years will pose unique challenges for businesses. Although some sectors will be more directly affected than others, none will be unaffected. At present, the only certainty is the likelihood of potentially significant changes to the legal and regulatory framework in which business is done in the UK.