This Evaluation Study was prepared for the European Commission – Directorate General for Taxation and Customs Union and it is intended to contribute to the forthcoming evaluation of the VAT invoicing rules, and, in particular, of those affected by the Second Invoicing Directive. This Directive was well transposed by the Member States, with only minor exceptions of a very limited relevance. The Second Invoicing Directive was one of the factors in supporting the growth in the use of e-invoicing technologies among EU businesses since 2014. This resulted in EUR 920 million savings over the period 2015-2017, of which about EUR 540 million in 2017. Those savings represent the bulk of the administrative burden reduction generated by this legislative act, which, overall, amount to EUR 1.1 billion over the 2015-2017 period. Differently, the Directive had a negligible impact on the fight against VAT fraud, as the simplifications to e-invoicing and invoicing rules did not affect tax control activities or caused costs for tax administrations. As its provisions were largely considered as working well by the stakeholders, few changes to the current legal framework are warranted in the short-term, and, whenever possible, by means of soft law instruments. In the medium-term, a revision of the VAT Directive to promote the use of automatically-processable e-invoices and the diffusion and harmonisation of additional e-reporting requirements may be considered.