Most states license the purchase of consumer debt because it involves working with sensitive personal information of debtors and requires compliance with the requirements of the CFPB and the best practices of working with debtors.
In the USA, several self-regulatory organizations also impose requirements for working with debtors on their certified members. The most famous organization is Receivables Management Association International (RMAI). Working with the buyers of this organization, you can expect higher standards of work.
Consumer debt buyers are divided into two classes - passive debt buyers (investor companies) and companies engaged in collecting independently; often, these are collection agencies that buy debt. Passive debt buyers act as investors. After the purchase, they provide debt to the collection agencies or collection attorneys for collection. In other words, they don't recover debt on their own. The second type of buyer uses its own capacity to collect debt.
Both types of buyers are represented on the Debexpert loan marketplace. You can find the full list below.