The existence or non-existence of a double taxation avoidance treaty has a decisive influence on the taxation of income that was earned abroad. The article deals specifically with earnings from dependent activity where, in the case of a double taxation avoidance treaty, taxes are largely paid in the country where the employer is located. At the same time, it draws attention to the exceptions, which if the employee does not know the exact wording of the treaty, can lead to considerable tax liability including accessories in the Czech Republic. The aim of the article is to point out the possibilities of conceptual solution of such exceptions.