DT20655 - Yugoslavia: Students
In addition to the normal provisions exempting students and trainees from Yugoslavia from United Kingdom tax on payments from outside the United Kingdom for the purpose of their maintenance, education or training, the agreement also exempts the earnings, not exceeding £250 during any year of assessment, of such a student.
In no case is the exemption to be given for a period of more than three years (Article 19). See also DT1930 - DT1931; any case of difficulty can be referred to Employment Income Technical.