Kinderzuschlag (child supplement)
Kinderzuschlag when the other parent pays no maintenance
If a child lives with you and the other parent pays no maintenance or too little, an additional sheet belongs with it: KiZ 5c.
It asks whether maintenance is agreed, whether it is paid and whether you have applied for an advance maintenance payment.
For every child affected a sheet of its own arises.
If you have not taken any steps
The official form asks about that, and it is not a trick question. There are fields for “no application made” with room for the reason. You do not have to claim anything that is not true.
When the other parent is unknown
There are fields for that too — for instance when paternity is not settled or the address is not known. What you do not know stays empty.
What that costs
The price depends on how many children you are applying for the supplement for. The sample calculations are on the page about Kinderzuschlag (child supplement).