With an investment of over 700 million euros, the public sector is the main advertiser in the Spanish market. Altogether, the central, regional, and local governments launch more than 5000 institutional advertising and communication contracts. In Spain, these tenders are governed by Law 9/2017 on Public Sector Contracts and Law 19/2013 on Transparency, Access to Public Information and Good Governance, in compliance with which governments have developed openly accessible websites that provide practical information on the contracts for interested individuals and companies. This paper compares all regional procurement platforms through the study of a hundred institutional communication public contracts launched in 2021, assessing the usefulness of the published content, detecting good practices, and identifying gaps and areas of improvement. The results obtained support the idea that these platforms do not provide exhaustive information on public contracts, which limits their potential as tools aimed at ensuring competition and transparency in public contracts. Based on this last criterion, a ranking is created among the regions analysed.Agencia Estatal de Investigación | Ref. PID 2021-124293OBI0
