It depends on the specific policies of the store and the prepaid card in question. Some stores may have age restrictions on purchasing magazine subscriptions with prepaid cards, while others may not. Additionally, some prepaid cards may have restrictions on the types of purchases that can be made with them, which could include magazine subscriptions.
In general, it is always best to check with the store or the prepaid card issuer to determine if there are any restrictions on purchasing magazine subscriptions with a prepaid card.