Security for costs is increasingly being used in international commercial arbitration, even where the parties are solvent. However, the tribunals outside Commonwealth jurisdictions have been apprehensive about granting such a measure. The general position is that, absent agreement to the contrary, the tribunal has a mandate to grant any interim measures including security for costs; there is no uniformity in standards governing the power to exercise the mandate. The criteria for evaluating security for costs applications differ from typical interim measures applications, as they require the party seeking such a measure to establish exceptional circumstances comprising considerations including a deterioration in the financial situation of the party since the time of the agreement and third-party funding. Third-party funding has become very common in international arbitration. However, the relevance of third-party funding as a basis for security for costs is contentious, due to the lack of any regulatory framework. This article also throws light on the inherent mandate of the tribunal to grant such an interim measure, the considerations necessary to exercise this mandate and the circumstances warranting such a measure. The article differentiates considerations for security for costs from other interim measures.