As a result of the decline, the total number of new agreements in the final month of last year was noted at 1,526.
In monitory terms, this equated to £62m in the value of new business.
Looking to the three months to December, the number of new agreements was down 30% at 5,100, which equated to £205m – a 37% drop.
On an annual basis, the number of new agreements was 17,109, a 39% decease year-on-year.
Overall, this number of agreements meant the value of new business over 2020 was £727m.
Fiona Hoyle, head of consumer and mortgage finance at the Finance & Leasing Association (FLA), said: “The second charge mortgage market has seen new business levels gradually pick up since the crisis-low reported in May 2020.
“The quarterly rate of contraction has eased – compared with the same period in 2019, new business volumes fell by 73% in Q2 2020, by 52% in Q3 2020, and by 30% in Q4 2020.
“With consumer confidence expected to improve as 2021 progresses, demand in this market is expected to increase.”