The business has previously created its ads in-house, but is planning a bigger marketing push for the brand, which will include press, radio and direct marketing.
Kevin O'Shaughnessy, Purple Loans' marketing director, is leading a pitch, which is being held between three undisclosed agencies.
Last year, GE appointed Carat to its £20 million media planning, buying and strategy account for the Purple Loans and First National brands.
Purple Loans offers secured loans and mortgages to people who have difficulty getting them from mainstream lenders because of a poor credit rating or employment history. Last year, personal debt levels in Britain broke through the £1 trillion level for the first time.
Purple Loans' parent company, GE, provides financial services to retailers and consumers in 40 countries. These include personal and auto loans, mortgages, credit insurance, debt consolidation and home equity loans.