Collaboration among revenue authorities around the globe is increasing. In addition to traditional information exchange under tax treaties and agreements, many countries now engage in other collaborative activities, including bilateral advance pricing agreements, Competent Authority agreements, and multilateral tax information exchange programs (e.g., the Joint International Tax Shelter Information Centre (JITSIC)). Countries also have been engaging in simultaneous tax audits, in which two or more countries examine a taxpayer simultaneously, each in its own territory, when there is a common or related interest and a view to exchange the information they obtain. This collaboration has continued to evolve into more sophisticated methods and strategies. One emerging audit trend is the pursuit of so-called joint audits, in which an individual or business is subject to a coordinated audit using a single audit team comprised of representatives from two or more jurisdictions. This new approach stands in contrast to the more typical situation in which the same taxpayer is subject to separate audits by two or more countries with respect to the same transaction or items of income or deduction. Joint audits are the next step to even greater cooperation between taxing authorities -- a new era of coordinated action.