The question of when an agent has ostensible authority to bind their principal has been the subject of several important decisions in recent years. That question arose again in Republic of Mozambique v Credit Suisse International & Ors [2024] EWHC 1957 (Comm) (Mozambique) in relation to whether the Mozambican finance minister had authority to enter into sovereign guarantees on behalf of the Republic of Mozambique (the Republic) with various lending banks. This article analyses some of the issues that arose in Mozambique in relation to ostensible authority and considers the “red flags” of financial crime relied upon by the Republic as putting the banks on inquiry that the finance minister did not have authority.