The aim of the study is to analyze how Swedish large fashion companies' sustainability reports quality has been changed 2016-2019. The study wants to create a deeper understanding of the legislative change initiated by the EU that Sweden introduced in 2017. Quality is declared to consist of the three categories of credibility, content and communication. The study's issue was: “How has the quality of fashion companies' sustainability reports been affected when they became statutory to be produced?”. The sample consisted of 14 companies. Some of the companies prepared joint sustainability reports which led to the number of sustainability reports that the study analyzed being 10 reports per year 2016–2019. An additional report was added for 2019 when a company chose to prepare a report separately from the parent company. A qualitative content analysis was used as a method to study the selected 41 sustainability reports. The theories and concepts used in the study for analysis were triple bottom line, institutional theory, stakeholder theory, signal theory and GRI. The results showed that companies' quality of sustainability reports have changed both in accordance with the EU Directive 2014/95/EU, but largely due to surrounding factors. The study has provided a deeper understanding of companies' sustainability reporting and shown that there is no unambiguous change in quality when sustainability reporting for larger companies became mandatory by law.