If you are sure that you have never used this company (be sure to look for the original creditor if this is a collection agency just in case). Then you can dispute directly with the credit bureaus and not even send a validation letter if you choose. I would wonder if you legitimately have never used this creditor if your information was included in a data breach. I would keep a close eye on your reports to see if anything else pops up. Given that these are new, and you just noticed them there is no harm in disputing directly for their removal. If the dispute is denied, then you can send validation or initiate contact to figure out why this is on your reports.