Supplementary Protection Certificates (SPCs) are European sui generis rights which provide a form of patent term extension available in Europe for medicinal products or plant protection products. The period of effective patent protection for medicinal products and plant protection products can be significantly less than in other sectors because of the need to obtain a marketing authorisation (MA). Obtaining an MA can take a significant amount of time (typically around 12 years), which can be a large portion of the lifetime of a patent (20 years from its filing date). SPCs are national rights available in individual EU countries (and European Economic Area (EEA) countries: Switzerland and Norway) which are governed by EU regulations. They will also continue to be available in the UK following its exit from the EU. The SPC sphere is a fascinating and extremely active area of intellectual property law. There is a steady stream of decisions from the Court of Justice of the European Union (CJEU) attempting to clarify the SPC Regulations, and there are a number of issues outstanding. This brief guide attempts to give a sense of the current state of play.