Book excerpt: BEPS Action 5 is one of the four BEPS minimum standards that all Inclusive Framework members have committed to implement. One part of the Action 5 minimum standard relates to preferential tax regimes where a peer review is undertaken to identify features of such regimes that can facilitate base erosion and profit shifting, and therefore have the potential to unfairly impact the tax base of other jurisdictions. This progress report is an update to the 2015 BEPS Action 5 report and contains the results of the review of all Inclusive Framework members' preferential tax regimes that have been identified. The results are reported as at October 2017. The report also contains guidance on preferential tax regimes, including timelines for amending regimes, how certain features of preferential regimes will be monitored, and guidance on the requirement that jurisdictions offering preferential regimes must require substantial activities to be undertaken in the regime.