Abstract: In performance-based research funding systems evidence of peer review is often considered a requirement for publications to be included. Originating from the sciences, pre-publication peer review is very common in the publishing process, also in the social sciences and humanities. Sometimes, however, it is ambiguous whether a publication is peer-reviewed or not. In this contribution, we analyse the ambiguity in identifying a journal’s or publication’s peer-review status by comparing the classification of journals in Finland and Flanders, and by taking stock of Finnish authors’ reporting of peer-review status of publications. We find that ambiguity in terms of peer review status is rather common, especially in the humanities. Indeed, we find differences in peer review status in about 10 per cent of all cases, both when comparing Finland and Flanders, and when comparing author-reported and centralised identification of peer-review status.