If you have one file to clean, you should be able to pay for that file and be done with it.
That is how the one-time checkout on /bulk works. Upload your file, choose the checks, and get a quote in dollars. You pay for that run. The next file gets its own quote, so there is no credit balance to top up or keep track of.
Before payment, the quote shows a sample of your own rows with verified results. It also shows how many unique values will be checked in each selected column. Repeated values are counted once per check, and empty or malformed values stay off the bill.
What happens when a check cannot give an answer
Some lookups finish with an unknown result. When the run completes, we calculate those results' share of your payment using each column's price. Completed one-time files retain the order minimum shown before payment, so refunds are limited to the amount paid above that minimum. We automatically refund the eligible amount to the original payment method when it reaches $1. Smaller partial refunds are not issued automatically or carried forward. Failed jobs receive a full refund, and the minimum never reduces a full refund. Existing files keep the refund terms shown before payment.
A negative answer is different from an unknown one. Finding that a number is disconnected, for example, is a completed check. That is useful information when the job is cleaning a list.
Paid file runs have a $5 minimum, and results stay downloadable for 30 days. If you already subscribe to a paid plan, bulk jobs use that plan's allowances instead of the one-time checkout.