Self-employed with a side business: two errors in the ČSSZ overview that cannot be fixed

ČSSZ warns that if a self-employed person does not mark an activity as a side activity in the annual overview, it counts as the main one, which costs more. The error cannot be fixed even with a corrective overview.

On 5 May 2026 the Czech Social Security Administration (ČSSZ) warned self-employed persons (OSVČ) with a side business that mistakes in the annual overview of income and expenses (for 2025) can be costly. The first error is not marking the activity as a side activity: it is then treated as the main activity, which brings mandatory pension insurance that is often much higher. The status cannot be changed after filing, even with a corrective overview. The second error is ticking 'ano' in part E by mistake, which means voluntary participation in pension insurance; the application cannot be withdrawn after the overview is filed. Before submitting, ČSSZ recommends checking rows 27 and 28 (the calculated assessment base) and row 34 (additional payment or overpayment). The advice is useful for next year too. Published for Ukrainians living in Czechia.