Income Protection (IP) specialist PG Mutual saw a 4.7% increase in its balance sheet, bringing it to a record £37m.
The society's results for 2014 also saw premiums increase by 3.8% and total policies increase by 3% compared to 2013.
A 3% interest rate for members along with a 25% terminal bonus have been announced by PG Mutual.
The society has maintained claims payment levels at 97% it also revealed.
PG Mutual is a registered friendly society specialising in income protection for professionals.
Mike Perry, chief executive officer at PG Mutual said: "As with every year, the PG Mutual team has worked really hard to improve on the previous year's performance, and once again I am delighted we have achieved it.
"We have spent the past year concentrating on improving processes and services.
"We are especially proud of our new member benefits scheme, giving our members best value deals and discounts on a wide range of products and services from well-known high street brands.
"What is most satisfying is seeing the growth in our membership and realising our message is getting through, that income protection is not an afterthought, it is an essential part of all of our personal financial budgeting.
"It is scary to think what might happen to us and our families if we were to lose our income due to illness or injury - our growth this year shows that people are no longer adopting the ‘it won't happen to me' attitude and are taking positive steps to protect their financial security and lifestyle."