One API is for enriching only work emails and another API is for enriching only personal emails so if someone mainly wants to enrich work emails, and it finds work emails, it will charge a credit but if it finds personal emails instead of work emails, it'll retrieve "Not found" and it won't charge any credits for the request. Same goes for personal emails. So if someone wants to enrich personal emails, it finds work emails, it will retrieve "Not found", and won't charge any credits for.