The document discusses the Open Government of Catalonia's efforts to promote electronic invoicing (e-invoicing) among public sector entities and businesses in Catalonia. It summarizes that: 1) The Open Government of Catalonia established a central HUB model to facilitate e-invoicing, handling interoperability, validation, archiving and feedback to reduce the burden on individual public authorities and businesses. 2) Through this HUB model, the percentage of e-invoices in Catalonia increased from 5% to over 90% in one year, resulting in estimated savings of €32 million per year from reducing paper invoices. 3) The HUB model provides a single entry point for e-invo