
You are planning a research stay in Germany and want to find out about taxation?
Research stay based on a fellowship:
If your research stay in Germany is supposed to take place in the framework of a fellowship you may, under certain circumstances, be exempt from taxation under German income tax law. It is certainly worth consulting the organisation which has awarded the fellowship on this point. Furthermore, you should find out whether the fellowship paid in Germany is subject to taxation in your own country.
Details on tax exemption on fellowships in Germany
Research stay based on an employment contract:
If your research stay is based on an employment contract in Germany and will last more than 6 months you will basically be liable to taxation in Germany on your globally-earned income and assets. If you stay for less than 6 months, your income will be taxed in your own country provided that you work for a foreign employer and the double taxation agreement assigns the right of taxation in such cases to the home country. If one of these conditions does not hold, your salary will be taxed in Germany. Agreements exist with some countries stating that higher education teachers and researchers who come to Germany for a maximum of two years to work on research in a public research institution may pay their taxes in their own country. Details can be found in the
double taxation agreements which exist in relation to the
Member States of the EU and certain other countries (
Overview of countries with existing double taxation agreements 
).
The income tax you incur will be deducted from your salary at source.
At the end of each calendar year you may apply to the
tax office in your place of residence 
to have your income tax adjusted ("Lohnsteuerausgleich"). This may entitle you to a partial reimbursement of tax paid. The necessary documents can be obtained from the
local tax office 
("Finanzamt") or
town hall ("Rathaus"). Often, it is worth paying a
tax accountant 
to help you complete your tax return.
Questions and answers on taxation
Further Information:
Double taxation agreements 
Texts of the double taxation agreements concluded by the Federal Republic of Germany as well as other state-related publications
Federal Ministry of Finance
Tax offices, tax forms etc. 
Information about tax offices, tax forms, electronic tax returns, tax allowances, laws
Federal Finance Office
Your Europe - CitizensInformation on your rights and opportunities in the EU and its Internal Market plus advice on how to exercise these rights in practice. Useful information on living, working and studying in another EU country, including taxation
European Commission
Database of tax accountants

Search for tax accountants in Germany, Europe and worldwide amongst other things by area of expertise (for instance "income tax") and by country on whose tax law the adviser is specialised
German Association of Tax Advisers