Abstract In many conflicts, aid organisations have to navigate the international humanitarian law requirement that parties to the conflict must consent to assistance. In non-international armed conflicts this often frustrates efforts to provide relief, as States refuse to grant consent in order to uphold their claims to sovereignty. Looking at the Syrian Civil War, this article suggests that the law of agency can offer a fresh perspective on the challenges posed by the requirement of consent to humanitarian assistance. It suggests that agency law can provide a legal explanation of seemingly political decisions and a de lege ferenda justification for assistance in instances where consent is either absent or provided by a non-State armed group.