Credits are separate from contacts. A search never spends a contact; contacts are used only when you reveal an email or phone you did not already have. That means you can search as much as you like and pay only for the people you actually take.
A failed search is refunded automatically. If BuzzAI cannot build a confident list, the credit goes back.
Sales Briefs and written emails use more credits than a search because they involve research and writing; the amount is shown before you start, and reopening a finished brief or sequence is free.
The Free plan does not include AI credits, but every filter BuzzAI uses is available by hand, so a free account can still build the same lists. See all plans.