Professor de la Feria was tax policy and legal drafting adviser to the Portuguese Government (2011-2012), and to the Government of Timor-Leste (2015-2016); has provided tax policy advice, and/or legal drafting advice to the Governments of Turkey, Uzbekistan, Mozambique, and Jordan, under the auspices of the IMF; and has assisted with the legal drafting of both the Angolan and Sao Tome and Principe’s new VAT laws, again under the auspices of the IMF. She has testified before the UK Houses of Parliament on international tax avoidance (2013), and online tax fraud (2017); before the European Parliament on tax havens (2017) and on VAT rates (2018); before the Parliaments of Timor-Leste (2016) and Sao Tome and Principe (2017) on VAT implementation; and before the Brazilian Congress on indirect tax reform (2020).

Professor de la Feria was listed two years running (2015-2016) in the Global Tax 50, by the International Tax Review, as one of the most influential tax people in the World; was co-recipient of the 2016 Outstanding Women in Tax Award, awarded by the Tax Analysts; and was recognised in the 100 Years of Women in Tax, as one of the most influential women in tax in the last 100 years, by the International Fiscal Association (IFA). She features regularly in general media outlets discussing developments in taxation policy around the world, and worked with the BBC Panorama and the Guardian as an expert on the “Paradise Papers” leaks (2017)