This paper introduces and outlines a new research area, Applied Language Typology (ALT). ALT builds on fundamental typological findings in morphology, syntax and semantics. ALT examines the attested and potential practical consequences of these contrasts for different professional contexts of communication, such as translation, the law and second language learning and teaching. The paper proposes three general organising principles that underlie ALT, illustrating how these principles enable to identify exact points of language contrasts that result in significant practical difficulty, and it suggests future directions in ALT research for the benefit of academics and language practitioners.