The owner of the payday loan brands Peachy.co.uk and Uploan.co.uk has collapsed, the town watchdog said.
The Financial Conduct Authority (FCA) said directors had been appointed for Cash On Go and was in contact with the company to ensure fair treatment of customers.
The regulator said: “All existing loan agreements remain in place and will not be affected by the proposed administration.
“However, the company is no longer able to issue new loans,” he added.
The Peachy brand claimed to have two million customers before its website was replaced with a message announcing the administration process.
Cash On Go is the latest in a long line of such lenders to exit the short-term loan market as a result of tightening regulations in the payday lending industry.
The largest remaining operator, QuickQuid, fell last fall just over a year after Wonga – at the time the UK’s largest payday lender – was plunged into insolvency in the middle a deluge of customer compensation claims.
The industry had faced strong criticism for its treatment of consumers, including lending to people clearly unable to repay short-term loans.
Other complaints concerned massive interest rates and opaque terms and conditions.
Smith & Williamson co-directors said on Thursday evening: “All outstanding loans remain subject to the terms agreed with COG (Cash On Go) and borrowers are to continue to make payments in the usual way according to the agreed terms and conditions. .
“The directors work with the company to facilitate an orderly liquidation of the business and initiate the process of identifying all creditors, in accordance with their legal obligations.”