This paper explores the role of the Power of Attorney and its closest Dutch equivalent known as the volmacht (plural: volmachten) more accurately translated as ‘mandate’ or ‘act of proxy’. Both the Power of Attorney and the volmacht were legal devices that transferred power to someone to act on someone else's behalf in a legal or business matter. These legal devices were heavily utilized by Arab merchants from Hadhramaut (in present-day Yemen) in order to authorize their representatives in the British Straits Settlements (Penang, Malacca and Singapore) and Netherlands Indies (Indonesia). Often conceived according to Islamic law, but administered according to British or Dutch legal procedures, these Powers of Attorney demonstrated how Arab migrants negotiated at least two very different legal systems to construct durable trust networks across the Indian Ocean. Originally written in Arabic, the Powers of Attorney were subsequently translated into Malay, and then further translated into English or Dutch. Court cases involving Powers of Attorney and volmachten illustrated common complications presented by these documents namely, jurisdictional complications, limitation of written documents as valid evidence in Islamic law, the uncertainty surrounding women’s agency in Islamic jurisdictions, translation problems and the complications of multiple versions of same documents competing for legal recognition. Heavy reliance on this particular legal device by members of the Arab diaspora firmly tied them to state legal institutions that authorized, ratified and enforced legal terms in these documents. In their desire for legal enforcement, members of the Arab diaspora entrenched themselves within political and economic hierarchies of formal legal colonial systems. These Powers of Attorney offer a window into the logistics of commercial operations across lands not ruled by a unified state or integrated by a common currency. The uniformity of style of these Powers of Attorney could be a testament to a truly global mercantile culture.