The status and classification of the Besermyan language, spoken by the northwest Udmurt Republic’s Cheptsa River residents, demand further investigation. The literature presents conflicting views, referring to it as a dialect or subdialect of Udmurt or a distinct language. The origin of Besermyan also sparks debate. While most contemporary linguists view it as a Udmurt dialect, others, like Y. Wichmann, suggest that the Besermyans are Tatars who assimilated into Udmurt culture. Studies examining the lexical and phonetic distinctions between contemporary Besermyan dialects and literary Udmurt, as well as other Udmurt dialects, have revealed that the core vocabulary of Besermyan is remarkably similar to literary Udmurt (94% of words from the 100-word Swadesh list coincide with each other). However, significant phonetic variations have been identified between Besermyan dictionaries and the audio dictionaries of Udmurt dialects. To comprehend what constitutes innovation—whether it’s the similarity in vocabulary or the differences in phonetics—this article will first examine the earliest Besermyan dictionaries, compiled in the 19th century, from the viewpoint of their graphics and lexical variations compared to dictionaries and concordances of other dialects created during the same era. Subsequently, the morphological dictionaries of Besermyan and other contemporary Udmurt dialects, as well as the literary language, will be analyzed, as morphology is thought to most accurately capture archaic similarities and differences. The graphical analysis of the earliest Besermyan dictionaries shows that in the 19th century, Besermyan was even closer to the northern and central Udmurt dialects than to the southern ones. A comparison of morphological affixes has also confirmed this conclusion. The innovative phonetic features of modern Besermyan dialects likely emerged over the last 150 years due to contact influences and cannot be used as a basis for the genetic classification of Besermyan.