This paper examines the role of international organizations as prominent terminological agents in dealing with neologisms from English in their areas of expertise. It focuses on the relationship between the institution's more or less exclusive competence in a field of neological work, the potential authoritativeness and impact of its terminological recommendations in that field, and the evolution of quantitative indicators of intra-, inter- and extra-institutional consistency of uses in the target language. A diachronic and comparative approach is adopted for the analysis of patterns of translation of four terms representative of three areas of international law (“governance”, “tariff peak”, “tariff escalation” and “hedge fund”) and various levels of terminological convergence in three institutional settings (the UN, the WTO and the EU), including publicly-accessible translations and terminological databases. These patterns are compared with the corresponding terms found in the Spanish general and economic press (including ABC, Cinco Días, El Mundo, El País and Expansión) and in published books (Google Books Ngram Viewer). The findings suggest a correlation between degrees of fragmentation of terminological work, perceived linguistic authoritativeness and levels of harmonization. They accordingly highlight the need for further consistency and coordination in order to improve the quality of institutional communication and, more broadly, the standardization of specialized terminology in the target language.