The Free plan renews with 100 fresh contacts at the start of every billing month, for as long as you keep using Buzzlist. There is no trial clock and no card on file.
Searching, filtering, saving lists and exporting what you have revealed are all free. A contact only comes off your 100 when Buzzlist hands you an email or phone number you did not already have.
What Free does not include: AI credits. That means no Sales Briefs, no written emails and no search in a sentence. You can read a finished brief before deciding whether that is worth paying for.