This chapter presents the core disciplines under the SPS and TBT Agreements, highlighting how they set requirements for regulators to balance their own public policy objectives with the WTO objectives of trade liberalisation. Such ‘balancing’ requirements result in obligations for regulators to ‘rationalise’ their domestic regulations in order to ensure their quality. This balancing is inherent to all measures under the scope of the SPS and TBT Agreements and stands out in the obligations not to discriminate and to adopt only measures that are necessary and/or based on scientific evidence. Ultimately, the purpose of this chapter is to highlight that transparency and related regulatory dialogue is fundamental to help both regulating Members and complaining parties in determining the consistency of domestic regulation with WTO SPS and TBT Agreements.