Tax authorities use provisional refund to compensate other tax claims
The tax authorities can compensate outstanding tax claims with a monthly provisional refund.
So this can mean that your monthly refund will be lower than in previous months. The tax authorities have the right to do this.
The tax authorities however need to consider that enough money should remain for you to be able to live. There is an income border which can’t be touched by the tax authorities. This minimum income is roughly € 928 per month for single persons and € 1,325 for persons living together, but will be different based on age and whether there is a child or not.