This is a translation (by DeepL and Margo Bargheer) of the quality standards for open access books that members of the working group of German-speaking university presses jointly compiled and published in 2018 (see Qualitätsstandards für Open Access Monographien und Sammelbände). They were the result of an intense discussion process. According to the members of the working group, the following standards determine the quality of open access books. While we are aware that for various reasons not all publications being available in open access nor all those services publishing open access can meet these standards, we formulate the standards open access for books should be judged against. Since the year 2018 several funding programs for open access books have emerged that need to rely on established and reasonable standards to judge funding eligibility. So by now there are more aspects to open access books than covered by our 2018 paper. However we are convinced that the following ones remain the key aspects for high-quality publishing of open access books. Accessibility Rights Quality Assurance Formats Metadata Calculations Marketing / Communication Usage metrics