Please, select the number of credits you need. You will need, at least, the same number of the total emails in your list. For example: if your list has 1900 emails, you must buy 2000 credits. If your list has 25000 emails, you must buy 40000 credits at once, or you can buy 20000 then come back and buy 5000 more.
IMPORTANT: List Cleaning Credits don't expire and are NOT REFUNDABLE. Unused credits will remain in your account for future use.