This paper outlines current work on the construction of a high-quality, richly-annotated and register-diversified parallel corpus for the English-Spanish language pair, as currently carried out within the framework of the MULTINOT project. The corpus consists of original and translated texts in both directions and is designed as a multifunctional resource to be used in a number of disciplines such as corpus-based contrastive linguistic and translation studies, machine translation, computer-assisted translation, computer-assisted language learning and terminology extraction. The paper describes the structure of the corpus -which includes four subcorpora: English originals (EO) and Spanish originals (SO), English translations (Etrans) and Spanish translations (Strans)-, the registers selected for inclusion in the corpus, and the methodology used to guarantee the quality of the processing steps to enrich the corpus with linguistic information at different levels.