Withdrawal from the European Union (EU) has seen the United Kingdom (UK) abandon membership of and formal influence over policy making in the EU and pursue a policy of disintegration from and minimal commitments towards the EU. Although the UK–EU Trade and Cooperation Agreement is strikingly lacking in ambition, it does involve a dense and complex institutional framework to manage relations. Moreover, the post‐Brexit UK–EU relationship includes a unique set of arrangements that keep Northern Ireland in the EU's customs territory and internal market for goods. These arrangements involve dynamic regulatory alignment and are managed by a dedicated institutional set‐up that has the potential at least to provide the UK ‘in respect of Northern Ireland’ with a particular decision‐shaping role with regard to applicable areas of the EU acquis. This article considers the initial operation of these sets of institutional frameworks and their potential for UK influence over the EU.