Payday lenders are not doing everything they can to make sure they lend responsibly, the Citizens Advice Bureau warned.
Russell Hamblin-Boone from the Consumer Finance Association, which represents payday lenders said he did not believe that it was the "activities of the larger lenders" he represented.
He said: "We've got standards in place which go over and beyond what our legal requirements are to make sure that we're lending to people responsibly, that we're lending to people who can pay back and that we're making sure we are treating people fairly."
The Office of Fair Trading said it has received confirmation from 48 out of 50 lenders that they intend to prove to the regulator that they are acting within the rules.
It comes as a charity has warned that "out of control" lenders are failing to act responsibly. An OFT spokesman said:
Of the 50 payday lenders that were inspected during the compliance review, 48 have confirmed that they will provide the OFT with proof that they are fully compliant, while two have surrendered their licences.
The OFT has also announced that it has formal investigations open into the practices of three payday lenders and, in addition, three payday lenders have also had their licences revoked since the review of the sector in March.