While the vast majority of publicly traded securities is now held through a complex network of domestic and foreign intermediaries, few countries have adapted their withholding tax collection and relief procedures to recognize this multi-tiered holding environment. It is therefore often difficult of impossible to make an effective claim for withholding tax relief. The OECD Treaty Relief and Compliance Enhancement (TRACE) initiative therefore has developed the Authorised Intermediary (AI) system. This standardised system allows the claiming of withholding tax relief at source on portfolio investments. It removes the administrative barriers that affect the ability of portfolio investors to effectively claim the reduced rates of withholding tax to which they are entitled pursuant to tax treaties or to domestic law of the country of investment. It minimises administrative costs for all stakeholders and enhances the ability of both source and residence countries to ensure proper compliance with tax obligations.