Phosphate groups are ubiquitous across the biological sciences as they serve as allosteric modifiers, solubility anchors or high-energy leaving groups (Figure ). As such, nature has developed a myriad of enzymes to shuffle phosphate groups between substrates and/or utilize energyrich phosphorylated cosubstrates to power otherwise unfavorable reactions (Fig. ). Examples of such enzymes span transferases, ligases and lyases and account for more than 10 million entries in the Uniprot database. Despite their prevalence, the experimental interrogation of many of these enzyme functions (particularly their kinetics) remains difficult since the detection of inorganic (pyro-)phosphate is not trivial in many biochemical assays. Notable previous developments toward this end include fluorescent phosphate binding proteins, fluorescent ionic dyes with tunable photochemical properties, chromogenic metal complexes and coupled enzymatic assays employing purine nucleoside phosphorylases and xanthine-oxidases to generate a UV signal. However, these methods typically only allow for the examination of a small experimental space, exhibit low selectivity, or employ expensive reagents unsuited for highthroughput experimentation (see the Supplementary Information and Table for a detailed literature analysis). Thus, cheaply available, operationally simple, and versatile methods, which are compatible with biochemical assays and high-throughput experimentation, are lacking. To close this gap, we developed PUB, a compact module for phosphate detection via UV-spectroscopic monitoring of 5-bromouridine phosphorolysis. Herein, we introduce the PUB module, outline its application to biochemical assays on various scales and illustrate its utility with selected use-cases.