This Checklist summarises the principal UK competition law issues to consider when establishing, structuring and operating a JV (JV), including UK merger control, the Chapter I prohibition of the Competition Act 1998 (CA 1998) and related filing or compliance questions. A JV may raise both merger control and competition law issues. Under the Enterprise Act 2002, there is no separate 'full-function' requirement. The question is whether the arrangements result in enterprises ceasing to be distinct, typically because one or more parents acquires material influence, de facto control or legal control over an enterprise. In the case of a start-up JV, the key UK merger control question is whether the activities transferred to the JV by one or more parents (or acquired from a third party) are sufficient to constitute an enterprise. Even where UK merger control is not engaged, the creation and operation of the JV may still need to be assessed under the Chapter I prohibition of the CA 1998. This Checklist focuses on UK issues, but also flags where EU or other merger control