The study integrates theoretical and empirical investigation, uses error-based analysis techniques to identify mistakes and classify them within major language subsystems. A case study methodology and descriptive statistics were used to explore the language of the chapter titles and article headings, applied error-based analysis techniques. The mentioned analysis was conducted by a number of professional legal translators. The analysis revealed that English version of the Code titles and headings under study contains 17% of grammar errors, 14% of vocabulary errors, and 7% of the graphic errors. The material below introduces most typical errors and ways for their identification and correction. The findings confirmed the research hypothesis on the challenges to the quality assurance regarding the translation of domestic legislation into a foreign language at the level of the legislation documents headings. The research confirmed the importance to go beyond the legal dictionary and encyclopedia entries, underlined the relevance and urgent need to more focus on the target language legislative sources of equal or similar branch and genre and academic practice in the respective areas. Therefore, the results can become the basis for future research on the theory of translation of legal texts and documents.