Anyone who is bringing or carrying cash or equivalent means of payment worth more than 10,000 euros (e.g. in his or her handbag, backpack, or suitcase), must orally declare the whole amount to the customs officer when asked about it.
The obligation to declare arises regardless of who is the owner of that money or payment deemed equivalent, and the purpose for which the cash and/or equivalent means of payment are carried across the border.
Example: A group of travellers is entering Germany from Austria by train: father, mother, and three children. The mother is carrying 40,000 euros in her handbag - money that belongs to the father and the children. A German customs official asks the group whether they are bringing cash or equivalent means of payment into the country. Because she is carrying the whole amount, it is the mother who must let the official know of the 40,000 euros.
It is not permitted, however, to distribute the cash or equivalent means of payment among a number of people in order to circumvent the obligation to declare or notify. If you do so you will be committing an offence that is punishable with a fine of up to one million euros.