This chapter examines how collective self-defence request needs to be issued. There are a number of unanswered questions about the necessary manner and form of such requests. First, the chapter analyses whether ‘open-ended’ requests will suffice, or whether they must be targeted at a particular state (or states). It then considers whether collective self-defence requests must take any specific form and, in particular, queries whether they can be inferred. Similarly, it examines whether a collective self-defence request must even be made publicly (or, at least, be publicised), or whether covert requests can suffice. Finally, the chapter engages with two questions concerning the timing of the request. These are whether the request must be made before the collective self-defence action begins, and whether the existence of a collective self-defence treaty arrangement between the relevant states suffices as a ‘request’ (or whether an ad hoc and specific request is still required in addition).