Country-by-country reporting aims at improving tax transparency by requiring multinational firms to disclose certain tax-related data on a per-country basis. The reports are supposed to help tax authorities in detecting abusive tax sheltering and – in case they are made public – to exert public pressure on the firms inducing them to pay their “fair share of taxes” in the countries where they operate. Article 89 of the Capital Requirements Directive IV obliges EU financial institutions to publicly disclose CbCR data for financial years 2014 onwards.In a related project, we collected and analyzed CbCR data of multinational bank groups headquartered in the EU for financial years 2014-2016. We now aim to use the newly build up dataset of approximately 300 CbCRs to investigate the reporting heterogeneity across the reports, both content-related and with respect to the presentation of the data. Ultimately, we aim to develop policy recommendations on how to improve the interpretability and the information content of CbCRs. Given the costs involved in collecting the data, it seems worthwhile to ensure that the way of presenting it does not disguise relevant information and allows for a consistent interpretation across different bank groups and countries. Our insights are important in light of the ongoing political discussions on the introduction of a public CbCR for all large multinational firms in the EU.