They don't report automatically to the tax office, but if they want to trace you they only need to ask. If the cards are registered outside EEA, it's harder for the tax office to request your data, but if you are involved in some criminal investigation they will report you in a minute.
Toggle signature
Expat in Hong Kong - There are two ways to conquer and enslave a nation. One is by the sword. The other is by debt. - John Adams