After you sign up for the Vantikcard, our partner Aion Bank will assign you a personal spending limit. This will be between 400€ and 1250€. When you have made a spend, the limit will be reduced by the amount of that spend. Directly after that the amount of your spending will be debited from your linked bank account. As soon as the debit was successful, your spending limit will be fully available again.
A short example: Your personal spending limit is 1250€. You go to the electronics store and buy a TV for 500€. Consequently, you still have 750€ available as spending limit. The next day the 500€ are debited from your bank account. Now you have the entire 1250€ at your disposal again.