Is there a way to ask for the credit card only at the end of the free trial?

I’m reading that the only way for a user to experience the premium content is to insert the card details and the only way to avoid inserting a credit card is by manually selecting a member from the admin and associate him with a complimentary plan.

My need is to have the user experience the full premium content for a month without putting any card details and then downgrade it to the locked version if he doesn’t upgrade (inserting the credit card details only at the end of the trial, if he wants to upgrade).

Is it possible?