In addition to amendments to the European Union (EU) value added tax (VAT) statutory law and the case law of the Court of Justice of the European Union (CJEU), various types of soft law have increasingly been used in recent years to elucidate the essence of EU VAT provisions. These include the guidelines issued by the EU VAT Committee which is a body explicitly enshrined in the EU VAT Directive. This article is aimed at discussing the significance of the EU VAT Committee guidelines from a legitimacy perspective. It will be demonstrated that they do not correspond to the ideals of inclusive governance that have long been advocated at the Union level and thus generally show deficits in input legitimacy. Some recent examples relating to the amended special scheme for small- and medium-sized enterprises (SMEs) will be utilized to argue that the EU VAT Committee guidelines can only be considered to have a certain level of output legitimacy. They can thus be useful as a legal opinion that national authorities and courts should take into account when interpreting and applying EU VAT law. However, they must therefore comply with the mandate of the EU legislature enshrined in Article 398 paragraph 4 of the EU VAT Directive.