Wait with the building application because of the child construction allowance

It is actually relatively simple: Since it is only pretended that the funding requirements (i.e., either actual registration = move-in this year or, if moving in only in 2020, income also below the income limit in the then relevant period) are met, it would likely be fraud if a move-in (which is only supposed to be proven by the registration confirmation) did not actually occur at the specified time... with a house that does not yet have any connections, this could also be quite easily verified through spot checks...

Due to the lack of a completion report, the occupancy of the building is not permitted at all. Ergo, there can be no legitimate re-registration there. Due to the lack of data matching, it may be that it (today) does not get detected. It is and remains subsidy fraud. Your perception of "waiving €24,000" is quite off. Apparently, you are not entitled to this subsidy; you have no claim to it. But: the average taxable income of the two calendar years to be considered counts. Have you taken that into account? In one of the two years, you can therefore exceed the limit as long as on average it is not exceeded.

Asking whether a registration is possible under the given conditions?
I would forgo €24,000 due to an exceedance of the income limit by 2 to 3 thousand euros in the assessment period.

Are you throwing the first stone right now?

you would like to take €24,000 from us (all) even though you are not entitled to it?

What an antisocial behavior... No claim is no claim, there will be numerous people who narrowly fail at the limit. (excuse the wording)

What counts is the taxable income - that is, after deducting the child allowances etc., and not the gross amount shown on the December statement. Maybe it will still work?

Otherwise: tough luck - especially since you also need the landlord's confirmation for the registration ...

We didn't need anything for the registration change. Just went to the town hall and changed the registration...