It also achieved pre-tax profit of £4.8m in 2020.
82% of intermediaries said they were extremely or very satisfied with the service they received from The Cambridge, up from 77% in 2019.
Its intermediary net promoter score was +64, up from +59 in 2019 and 99% of intermediaries said the society met or exceeded their expectations, up from 98% the year before.
Carole Charter, chief commercial officer at The Cambridge, said: “Our teams have worked exceptionally hard to continuously deliver for our Intermediaries during this unprecedented period.
“Despite the challenges they’ve been able to increase satisfaction and deliver enhancements to our proposition.
“It’s evident that our teams are absolutely in tune with the needs of our Intermediary partners and how integral they are to our success.”
Richard Brockbank, chief financial officer at The Cambridge, added: “I’m delighted by our strong set of financial results considering the challenging year we’ve all had.
“Maintaining long-term financial stability is incredibly important, and by delivering success in this area we’re truly a thriving, independent, mutual society.”