Usually, doctoral studies are financed through scholarships, employment as a graduate research assistant, or through jobs outside the university.

International PhD candidates who wish to work during their studies in Germany must adhere to the following legal provisions:

• PhD candidates from the European Union (EU), the European Economic Area (EEA), and Switzerland have the same rights as PhD candidates with German citizenship. They do not need a residence or work permit and may work in Germany without approval from the Bundesagentur für Arbeit (German Federal Employment Agency).
• PhD candidates from Bulgaria and Romania have the same residence rights as other EU residents and do not need a residence permit for their doctoral studies in Germany. In regards to employment rights, the 90/180 day rule applies, meaning they are allowed to work a maximum of 90 full days or 180 half-days (four or five hours). In addition, they are also normally allowed to work year-round as a graduate research assistant at the university, even if they receive a scholarship. However, the Foreigners Affairs Office and/or the scholarship grantor may impose restrictions. All other (part-time) jobs require permission from the Foreigners Affairs Office and the employment office.  
• PhD students from other countries are also subject to the 90/180 day rule. In addition to such a part-time job or scholarship, they are allowed to pursue work as a graduate research assistant year-round (see above). To facilitate this possibility, a note permitting such a part-time job and graduate research assistant work will be made in their residence permit.

• Employment as a scientific assistant requires prior approval from the Foreigners Affairs Office in charge.
• All employment exceeding the 90/180 day rule and exceeding the duties of a graduate research assistant also require prior approval from the Foreigners Affairs Office and the employment office. Students and PhD candidates are only allowed to work part-time. Employment must not change the reason for the student’s stay in Germany nor delay earning the degree.
• PhD students from Andorra, Australia, Israel, Japan, Canada, Monaco, New Zeeland, San Marino, and the USA are allowed to pursue every type of employment, provided that the German Federal Employment Agency approves and provided that the students meet the labor market priority review.  
• Priority review: The priority review means that a particular position may only be filled by an applicant from one of the above countries when neither German applicant nor foreigner from an EU or EEA country holding the same rights as a German citizen is available for the position.

If you are receiving a scholarship to finance your doctoral studies, you are normally exempt from (income) tax.

If you work to finance your studies, taxes and social security contributions will automatically be deducted from your income if it exceeds €400 per month.

For additional information, please click here.

Further information can be found in the brochure „Information about the legal provisions governing employment of foreign students, university graduates and research scientists" (only in German available) published by the German Academic Exchange Service (DAAD) on the right hand side of the screen or on the website of the City of Cologne.