"More people are remortgaging due to the uncertainty surrounding Brexit, and by using a cashback broker they are doubling their money in some cases."
Its data shows that just 4% of mortgages now offer cashback, with 20% of these only available to first-time buyers.
Despite the falling number of cashback deals, the average cashback offered has risen by over £100 since last year to £467.
CashbackRemortgages splits its commission with borrowers and says that if all homeowners used remortgaging brokers who share their proc fees, they would have been entitled to a share of £181m.
CashbackRemortgages says that on average it pays £690 cashback but this has risen as high as £11,000 on a single mortgage.
Suchit Sethi, founder of CashbackRemortgages, commented: "With only 4% of mortgage market products offering cashback, consumers need to wake up and realise they can get money for nothing by using a cashback broker.
“You would not rest on your laurels if you were overpaying for energy and phone products and yet, with one of the most important investments you can make, it’s mad to think that people are essentially throwing away free money.
"More people are remortgaging due to the uncertainty surrounding Brexit, and by using a cashback broker they are doubling their money in some cases. It is money for nothing and in the present climate people cannot afford to be throwing away these incentives."