If you are an employee of an Austrian company and spend more than 183 days in the given calendar year in Austria, you are obliged to submit a tax return in Austria and pay the income tax there as well. The same applies to owners of an Austrian sole trade (regardless of the length of stay). The amount of the tax depends on your income. However, if your annual income does not exceed the limit of 11,000 €, you are exempt from the tax and you do not have to submit a tax return. If you exceed the limit, the amount of the tax depends on the amount of your income. If you keep your permanent residence in Slovakia but you do not have any income in Slovakia, you must submit a (nil) tax return in Slovakia, too.