Adelin Stefan Yes, you can create a bank account as a minor at bunq as long as you have the permission of your parents / legal guardian. Same rules apply as for adults, you need to have be a Premium member in order to have a real bank account. But if you only want a single Mastercard (the Travel Card), then a Travel membership might be enough. Make sure you understand the different types of memberships, if you have any questions that you cannot find an answer to feel free to ask.
Some more information about the parent / legal guardian permission thing: https://together.bunq.com/d/2961-how-do-i-open-an-account-for-my-child