VAT grouping has become more and more popular across the European Union, such that only a few Member States have remained with no such option (or, rarely, duty) for the taxable persons. However, the VAT Directive provisions on VAT grouping remain relatively high-level, leaving many questions at the discretion of the Member States. In this article, the author identifies some domestic specifics and discusses the impact of domestic VAT grouping legislation on the deductibility of input VAT and adjustments of deductions.