Standards are essential for the circular economy; they are a means of communication and help to transfer information and find suitable partners and materials to close the cycle. They thus play an important role in the transformation of the linear economy to a circular economy. This chapter starts by exploring how standards are created, which other deliverables (specifications, technical reports, and CWAs/IWAs) exist, and who develops standards. This leads to the committees which are partaking in standardisation for plastics in the Circular Economy and the standardisation activities on plastics recycling (including less conventional forms of recycling, such as organic/biological recycling) and recyclates, the relevant committees on the one hand, and the standards and specifications dealt with by them on the other hand. Regarding European standardisation activities this includes the Standardisation Request M/584 developed based on the work of the Circular Plastics Alliance (CPA) initiated by the European Commission. Finally, emerging issues in the field of plastics recyclates, recycling, and bio-based plastics are addressed.