02/06/2025
Do you want to generate additional income alongside your fixed job through your personal project? Or gradually take the step into entrepreneurship? Becoming self-employed as a side activity is an interesting intermediate step. What are the advantages, and what should you pay close attention to? Here’s a clear overview.
The first advantage is the ability to generate additional income without giving up the security of salaried employment. A side activity allows you to combine two sources of income. You maintain the stability of your fixed salary while developing your own business. You also remain free to decide how much time you dedicate to it. A busy period in your main job may lead you to temporarily slow down. On the other hand, more availability can be turned into additional income.
The second advantage is social protection. A side activity does not affect the social rights linked to your salaried job. You continue to build pension rights through your main activity. You remain covered in case of illness or incapacity to work. In the event of dismissal, you also retain your right to unemployment benefits.
A third advantage is the possibility to deduct certain professional expenses. Costs incurred for your business can be deducted from your taxable income. This may include, for example, professional equipment, travel expenses, part of your internet costs, or even part of your rent if you work from home. If your activity generates a loss, these costs can even be offset against the income from your main job.
However, an important condition must be met. Deductible expenses must be incurred to obtain or maintain professional income. Expenses without a real link to professional income are therefore not deductible.
The first point of attention is taxation. The Belgian tax system is progressive. Income from your side activity is added to your salary and taxed together. It often falls into a higher tax bracket. If you want a more precise view of your net income, you can consult the dedicated blog article on this topic.
The second element concerns social contributions. Income generated from your side activity is subject to social contributions. Since your social rights are already covered by your salaried job, these additional contributions do not create extra rights. They do not increase your pension or sickness benefits. Reducing your working hours as an employee to focus more on your side activity may even reduce the social rights built through your main job.
Finally, a side activity also comes with additional administrative obligations. You must keep accounts, possibly submit VAT returns, and complete part II of your tax return. A late submission, a forgotten declaration, or an error may result in fines and interest.
Moving directly into full-time self-employment can feel risky. For many entrepreneurs, a side activity is a valuable testing phase. It allows you to assess whether your idea is viable without immediately leaving your job. You can gradually build your client base and experience before deciding whether a full-time transition is realistic.
Some people choose to maintain this hybrid model long-term. Combining salaried work with a personal project offers a balance appreciated by many entrepreneurs. From that perspective as well, a side activity can be a very relevant choice.
A side activity requires time and organisation. Administrative and accounting tasks can quickly become demanding.
PIA Go! offers a simple and effective solution. You get access to an intuitive digital platform to manage your accounting, along with an experienced accountant who handles the technical aspects. This allows you to focus on your activity while your accounting is carefully managed.
Do I need to register with a business registration office if I start a side activity?
Yes. Even for a side activity, registration with an accredited business registration office is mandatory. You will receive a company number, and your activity will be registered in the Crossroads Bank for Enterprises (CBE). PIA Go! can assist you with these steps to ensure nothing is overlooked.
Do I always need a VAT number for a side activity?
Not necessarily. If your turnover remains below a certain threshold, currently set at €25,000, you can opt for the VAT exemption scheme. In that case, you do not charge VAT and do not need to submit VAT returns. If in doubt, PIA Go! can analyse the most suitable option for your situation.
How much social contributions do I have to pay as a side entrepreneur?
Social contributions are calculated based on the net taxable income generated by your side activity. If your income is low or non-existent, only a minimum contribution is due.
Can I become self-employed as a side activity if I am a civil servant?
This depends on your status and employer. In many cases, prior authorisation is required.
What happens if I stop my main activity and continue only my side activity?
In this situation, your status automatically changes from side activity to main activity. Your social contributions and administrative obligations will change accordingly. With PIA Go!, this transition can be handled smoothly and without administrative complications.
