HANDBOOK - Raúl Félix Junquera-Varela and - Cristian Óliver Lucas-Mas

In recent years, the adoption of technologies by revenue administrations has contributed to the better provision of e-services to taxpayers and the strengthening of tax compliance control mech- anisms that can contribute to the increased collection of tax revenue. [...] This involves an interesting question that consists of establishing the extent to which presumptions can contribute to the simplification of tax administration without fundamentally altering or substi- tuting the essence of their respective tax bases and the original nature of the tax itself. [...] The legal and regulatory powers vested in the tax administration by all tax legislation—for example, tax procedure code and complementary regulations—can facilitate administering tax laws in an efficient way or, on the contrary, can impose significant constraints and impediments to the operational performance of tax administration (Faria and Yücelik 1995). [...] Some countries have a tax procedure code that encompasses the powers granted to the tax administration agency to administer the tax system, taxpayers’ rights and obligations, and the 1 REVENUE ADMINISTRATION HANDBOOK elements and key features of the basic processes of tax administration such as collection, reg- istration, tax audit, tax disputes, tax rulings, and collection enforcement of tax debt. [...] It is primarily meant to increase the transparency of the tax system and to allow the legislature to debate and review the provisions annually and get a sense of the rev- enue loss involved (Junquera-Varela 2011).