The Consumer Finance Protection Bureau has asked five major "buy now, pay later" providers for information on their practices and how they affect consumer debt.
Affirm, Afterpay, Klarna, PayPal and Zip have been asked for information and data by the CFPB.
The CFPB is looking into both consumer debt as well as consumer protection laws and what data these companies are collecting, according to its announcement of the inquiry.
"Buy now, pay later" companies have grown quickly as an alternative to credit cards. But they've sought to avoid regulation by seeking to not classify shorter-term payment deals as loans. This has raised concerns from regulators, as advocates have pointed out the deals can raise risks for consumers because of how companies often approve consumers for offers without doing full credit checks.