The figure is up from 45% of borrowers in the same period last year.
Furthermore, the data reveals the average LTV on mortgage applications was 72% last month, an increase on December’s ratio of 70.9%.
The report notes this rise is partly a result of an increase in the availability of LTVs above 80% in the past three months.
Brian Murphy, head of lending at Mortgage Advice Bureau, says it is not surprising to see consumers retreat to the safety of fixed-rate products.
He says: “With a variety of fairly negative economic news, rising inflation and an increase in unemployment levels, borrowers who are active in the market are erring on the side of caution and increasingly opting to fix their repayments.
“Furthermore, fixed-rate deals still offer extremely good value relative to historic levels and therefore we are seeing more people taking advantage of current pricing.”
The index also reveals the average loan size on mortgage applications increased by 6.6% in January compared to the previous month to £128,887, while the number of mortgage applications was up by 23.3%.
Murphy attributes much of the rise in volume to the treacherous weather conditions of December, which caused many transactions to be carried over into January.