In addition to storage of, it is mainly reaching the VAT registration threshold of a country which requires sellers to register for VAT in additional EU countries.
This VAT threshold is a limit which is set individually by each country, above which local VAT registration becomes necessary. How do you reach this limit? For this, the turnover from exports to the target country within a calendar year is considered. In Germany, the VAT delivery threshold is €100,000.
Example: If a seller who is registered for VAT in France sells to Germany, he must register for VAT in Germany as well as soon as he is about to sell goods worth more than €100,000 from France to Germany within one calendar year.