You will notice that the methods used for calculating the values for the 720 are very similar to that of the wealth tax.
If you file the 720 and it looks like you have more than the minimum threshold of assets, expect to get a nasty letter in the future if you don’t subsequently file the wealth tax.
However, there are several instances where the calculations will end up differently.
The most important difference happens when you buy a capital asset (like a house or stock), or pay off a loan, or receive a loan in the last quarter of the year.
Worst case example, let’s say you have 500.000 euros in a foreign bank account that you use to buy a house in Germany Dec 31st. Your modulo 720 Your average balance is 500.000 plus you have a house worth 500.000.
However, for the purposes of wealth tax, you would exclude the 500.000 from your average balance calculation and end up with a bank balance of 0, plus a house of 500.000.
Here’s a good link on the subject.