PROTAX contributed to the development of a European Security Model in the area of taxation. In WP1, PROTAX analysed case studies involving tax crimes and illicit money flows which provided insights into the daily work of LEAs and the judiciary including the challenges in preventing, investigating and prosecuting cross border tax crimes. VAT-Fraud was found to inflict significant losses to MS. This analysis showed dual use of enablers tax crimes. The most significant challenge was the lack of an effective inter-agency and transnational cooperation among the EU MS. In WP2, focus groups (FGs) were conducted with experts. A detailed questionnaire explored institutional practices in anti-money laundering and tax evasion. These FGs demonstrated that tax crimes are fuelled by legal, institutional, socio-economic, cultural, and behavioural factors. PROTAX explored these and added a new dimension, the human factors. In WP3, PROTAX provided a comparative analysis of the legislative and institutional approaches to tax crimes in 16 jurisdictions. This analysis revealed the differences in the volume of tax crimes; scope and definitions; thresholds; sanctions; investigation and prosecution routes; liability of legal entities; money laundering; organised crime; and whistleblower protection. By doing so, PROTAX created taxonomies of tax crimes and underlined the need to harmonise their treatment in the EU. Secondly, PROTAX developed a pioneering investigation into the relationship between tax crimes and corruption offences and analysed the legal frameworks to counteract “fiscal corruption” and suggested a whole-of-government approach against tax crimes and corruption. Thirdly, PROTAX explored the human factors through an analysis of the extra-legal, social, institutional and organisational aspects. In WP4, PROTAX explored why some countries are more successful than others in convicting tax crimes; and found that each country addresses tax crimes differently, and the statistics collected and analysed in each jurisdiction in the EU are fragmented. This study recommended that all countries shall standardise and publish their statistics. Additionally, PROTAX created a set of benchmarks for the adequacy of specific enforcement practices. In WP5, the PROTAX addressed the challenges in information-sharing. PROTAX analysed the current state of frameworks for cooperation and information sharing at national, EU, and international levels and developed a Policy Paper calling for an EU agency for countering tax crimes; and offered alternatives for positioning and operationalising a suitable agency. In WP6, PROTAX addressed data protection, privacy, ethical and social issues arising from the prosecution of tax crimes. These considerations are relevant as surveillance of individuals and data sharing between LEAs are keys to investigating tax crime. They impact privacy rights, data processing and control over personal data, and must therefore be proportionate and legitimate. In WP7, PROTAX developed toolkits for policy-makers, LEAs, and a risk assessment methodology. The toolkit for policy-makers provided a novel and proven policy streams from which actionable plans and laws can be developed to overcome common policy problems. The tax fraud investigation toolkit sets common standards and methods for LEAs and tax authorities. It was co-created with expert stakeholders. PROTAX also developed a tax crime risk assessment methodology which aims to offer a model of assessment of suspicious behaviours and warning signs as well the legal and institutional risks across the EU. In WP8, PROTAX conducted workshops with stakeholders across 19 European countries to demonstrate and discuss the toolkits. Additionally, PROTAX developed training materials and run masterclasses for the European Financial and Economic Crime Centre and various ministries. These efforts ensured that the toolkits were validated in a significant number of EU MS. Furthermore, PROTAX developed a series of recommendations for the EU Commission, and political institutions of the EU. In WP9, PROTAX developed various activities aimed at ensuring the take-up of the project’s results. Press releases and short articles were published on the project website and the social media. Additionally, PROTAX developed digital resources; clustered with relevant EU-funded projects and published its findings in prestigious books and journals.