There is a (refutable) presumption that anyone who is considered "a self-employed person" by the tax administration, is also considered in that capacity for his social status. Anyone who exercises a professional activity in Belgium that could result in income as intended by Article 23, §1, 1° or 2°, or in Article 30, 2° or 3° of the Income Tax Code 1992, is presumed to be liable for insurance.