Research by YBS showed that 2.3m borrowers are on SVR, accounting for 28% of the total mortgage market. Yet, with the average SVR currently 5.04%, the lender claimed that consumers could be missing out on savings of up to £1.8bn by not taking advantage of the best-buy deals available well below SVR.

However, YBS warned that 440,000 SVR customers are trapped on high LTVs above 85% and cannot remortgage to a better rate due unless house prices rise further or lenders relax their criteria to offer more competitive 90% or 95% LTV deals.

YBS estimates that for every 1% rise in UK house prices, around 16,000 SVR mortgage payers will be able to qualify for better deals by lowering their LTV.

Tom Girling, mortgage product manager at YBS, said: “The vast majority of SVR customers could make significant savings by switching to a better rate mortgage and with 80% having at least 15% equity in their home, they are free to switch lender right now.”