The article raises the problem of recording non-Russian toponyms by origin on topographic maps and in official reference books, which is relevant for cartography, as well as for the regulation of geographical names in general, including the State Catalog of Geographical Names. The authors analyze the models for the transmission of complex geographical names of Karelia, which arose on the basis of the Karelian language, which, together with a number of languages of the eastern Baltic area (Finnish, Estonian, Vepsian, etc.), belongs to the Baltic-Finnish group. Objective difficulties caused by the typologically different structure of the Baltic-Finnish and Russian languages, as well as the dialectal heterogeneity of the Karelian language are noted. However, incorrect spelling is often caused by cartographers` ignorance of the language and the peculiarities of local toponymy, as well as the lack of instructions for transmission Karelian place names into Russian. Three problems are considered in the transfer of a geographical term in Karelian complex toponyms. A large variability in the appearance of Karelian topographic terms is revealed, caused by the presence of not so much dialectal phonetic forms (-суари, -шуари `island`), as variants that appeared as a result of their incorrect display in Russian (-сари, -шари, -шаари, -сварь). The unlawful removal of the nomenclature term from the complex toponym is noted, leading to a change in the appearance of the whole layer of the original Baltic-Finnish names of the republic, and, as a result, a rethinking of their linguistic origins and meaning (Lake Kuarniz|järvi ‘Crow Lake’ → KarnIz ‘Cornice’). There is also an inconsistency in the spelling of compound complex toponyms: besides the hyphenated spelling (River Pieni Kivioja → Пиени-Кивиоя), recommended by the instructions, there are also toponyms written together (mountain Pieni Lohivuara → Пиенилохиваара). Errors in the transmission of geographical term in complex Karelian toponyms can be reduced to three main cases: variability in the look of Karelian nomenclature terms caused by their incorrect recording (-сари, -шари, -шаари, -сварь, суари, -шуари ‘island’); unjustified removal of a nomenclatural term from a complex toponym, leading to a rethinking of Karelian names (Lake Kuarniz|järvi ‘Crow Lake’ → KarnIz ‘Cornice’); inconsistency in the transmission of compound complex toponyms. Correct forms of Karelian geographic names of a complex structure on maps and in various kinds of official reference books and lists are proposed. It is noted that researchers of place names should be involved in solving the problem of adequate display of non-Russian geographical names in the language, both at the stage of compiling instructions and directly correcting toponyms, which is relevant for multinational Russia.