Two in five contractors (42%) earn more than they did in staff jobs, while 45% have been working for more than two years and 17% for more than 10 years.
Kensington estimates that 1.23 million people are currently working on full-time or part-time contracts.
Sarah Green, head of sales and marketing at Kensington, said: “Contractors, who can earn steady income despite not having the security of a regular payslip, can prove troublesome to some lenders.
“However, the world of work is changing. It is clear the number of contractors is increasing and that in many cases they earn more than they would in staff jobs.
“Kensington treats customers as individuals. Our underwriters assess each application on its own merits and we will always look to lend to a contractor who fits our criteria.”