The Consumer Financial Protection Bureau warned Monday online lenders could cost consumers more.

“While some marketplace lenders may advertise lower interest rates, in some cases consumers could lose important loan-specific protections by refinancing an existing debt,” the agency cautioned.

As an example, the CFPB said individuals paying off federal student loans could find it costlier to refinance through a private lender because they could lose several benefits including payments scaled to their income.

Online lenders can also make student loan repayments more expensive, as well, by switching the borrowers to variable interest-rate loans from fixed-rate loans.

Service members were warned online borrowing would lose them important protections they have on debt they incurred before entering active duty.

The agency has begun accepting complaints about online lenders at www.consumerfinance.gov/complaint.