The Korean tax and customs authorities have stepped up their enforcement activity over the years to ensure that cross-border transactions carried out between local subsidiaries and their overseas affiliates are conducted on the basis of an arm’s length price. However, the arm’s length price as determined by one authority (usually after an audit) may not be acceptable to the other authority, often resulting in a situation in which the taxpayer is effectively taxed twice on the same transaction. This article explores the conflicting positions taken by tax and customs authorities with regard to the arm’s length price, reviews the attempts made by the government to mitigate such conflict and provides some planning ideas to help manage risks around the arm’s length price from both tax and customs perspectives.