Legal discourse is widely assumed to be resistant to change, and indeed legislative documents are extremely conservative with fixed and formulaic structures. However, recent research has shown that changes can be observed in the lexico-grammatical features of some legal documents when examined diachronically, particularly since the emergence in the 1970s of the Plain Language Movement, which sought to draw attention to the unnecessary complexity of the official language, this including legal discourse. Despite the crucial changes in legal language in recent years, research in that direction is scarce to date, particularly in the British English variety, probably due, in part, to the shortage of specialised corpora that allow this kind of studies. In order to bridge this gap, we have embarked on the compilation of the Corpus of Contemporary English Legal Decisions, 1950–2021 (CoCELD), a corpus of British judicial decisions produced between 1950 and 2021. In this paper we present the structure and characteristics of CoCELD, as well as the methodology used for its compilation. The new corpus, which was released in February 2022, contains sample texts of roughly 2,500 words for each year from 1950 to 2021, which adds up to more than 730,000 words. The corpus contains files in raw text and with POS-annotation, and is freely available for the research community under signed consent. With CoCELD we hope to contribute with a new, useful resource for linguists with an interest in legal language, from both a synchronic and a diachronic perspective.