Historians have been working on medieval accounting records for a long time, but it is only a few years since some of them became interested in the study of the language of these texts. At the same time, paradoxically, very few linguists focus their research on these documents. Yet those are numerous, various and rich. But they also have to be studied with care and caution, not in a naive way, because their language shows several facets: some parts of these texts are more or less "fixed" like the "gangue" of presentation we find from a document to another at the same place for the same series, which changes only slightly over time. Others are rather spontaneous, in particular the one in direct and indirect speech. Therefore, their analysis will not be the same. Several issues can be studied in these texts, among which lexicon, syntax or oral speech which can be found in fines transcribed in the section devoted to revenues. But in order to conduct large-scale research, we need to constitute a corpus of interdisciplinary digital editions of these medieval accounting records.