Purpose This study examines how secrecy culture influences the communicative value of key audit matter (KAM) disclosures in Europe. It also investigates whether this association is moderated by Big 4 affiliation. Design/methodology/approach We use a range of regression analyses and various robustness tests for a sample of 13,203 nonfinancial firm year observations across 27 countries in Europe from 2016 to 2022. The communicative value of the audit report is measured by the number, length, readability, specificity and standardized language of KAM disclosures. Findings Auditors in higher secrecy cultures disclose fewer, less readable, and more standardized KAMs, reducing the communicative value of the auditor’s report. Big 4 auditors produce longer but less readable and less entity specific KAMs with greater standardized language in more secretive environments, indicating that global template standardization can reinforce, rather than mitigate, cultural restraint in disclosure. This highlights a regulatory paradox: although ISA 701 aims to enhance transparency, its effects are not realized uniformly across cultural settings. Originality This study provides the first systematic evidence on secrecy culture and KAM communicative value. By incorporating the moderating role of Big 4 networks, it shows how global audit methodologies interact with local cultural norms, offering practical insights for regulators and firms seeking to achieve the communicative objective of ISA 701.