Electrocatalysis on high-entropy alloys (HEAs) is a very young field. There are only a few articles on the theoretical understanding of catalysis on these surfaces. Activity descriptors and a ‘theory of catalysis’ exist for uniform surfaces. In this article, we address scaling relations and Brønsted–Evans–Polanyi relations on HEAs which are fundamental for finding activity descriptors. We find that some relations hold, whereas others disappear on HEAs. This reveals some of the future challenges in modeling electrocatalysis on HEAs.