Introduction

International arbitral tribunals consistently award interest to prevailing parties as compensation for the temporary withholding of their money.[1] The Iran-United States Claims Tribunal has noted that 'it is customary for arbitral tribunals to award interest as part of an award for damages', even in 'the absence of any express reference to interest in the compromis'.[2] Indeed, arbitral tribunals' inherent authority to award interest is so well recognized,[3] and is of such fundamental importance, that the right to interest has become part of the lex mercatoria.[4]