Pursuing a degree can lead to countless expenses, but luckily for students, a number of them can be claimed on their tax return. As tax refunded by the government must have already been paid, this is considered a loss carryforward (Verlustvortrag) - however, since most students' income falls below the tax-free amount, they can secure a tax bonus for their future career by filing a tax return and carrying forward losses.
If a student has more expenses than received income in a given year, the tax office (Finanzamt) takes this into account and uses it as a "tax bonus" as soon as the student begins paying taxes.
If a student paid tax on their income, they can report their education expenses directly on their tax return and a loss carryforward is not necessary. In this case, there is an immediate tax refund.