This kind of activity is called the sharing economy: goods and services are provided from one person to another, either free of charge or against a low price. Typically, the activity relies on digital marketplaces.
Examples of services within sharing economy include the rental accommodation provided by Airbnb, Pop Up restaurants and blogs.
The income derived from this activity is subject to income tax, and it must be included in your normal tax returns. However, you are entitled to deduct the expenses that are caused by the production of the income.
Pay the taxes already in 2019 as prepayments or by raising your withholding percentage rate
You can report your income already during the income year, so the tax office can determine the appropriate prepayments for you.
Submit information on the income by raising your withholding percentage rate
If your income (subject to prepayments i.e. the income from the activities listed above) is a maximum of €7,000 in total, you can include the income on your tax card.
The Tax Administration performs a calculation of your total taxes after each year, in order to determine whether you have paid enough tax-prepayments on your income. If it turns out that you have paid too much, you receive a refund. If you paid too little in prepayments and withholding, you must pay back taxes.