Moneynet.co.uk says vast numbers of UK borrowers have borrowed themselves into a position of vulnerability in order to buy property and are not in a position to remortgage.
Nearly 35% of respondents to its recent survey are juggling a mortgage debt more than three times their gross annual salary.
The website says that of these, nearly 30% are unsure whether they would be able to provide proof of their income to a new lender
Both factors seriously weaken their ability to secure affordable loans in the future.
Richard Brown, chief executive of Moneynet.co.uk, says: “Many of these borrowers are likely to find it very difficult to remortgage now that the days of easy borrowing have come to an abrupt end.
“Fewer and fewer lenders will be prepared to offer competitive alternative deals to anyone who is considered at risk of default. These borrowers will have little choice but to accept what their present lender is prepared to offer when their current deal comes to an end.”
The site says there will be vast numbers of people finding themselves in this position in the near future.
Nearly half of those surveyed are on a fixed or discounted deal and 55% of them are likely to experience payment shock this year.
Moneynet.co.uk says nearly 30% of respondents have borrowed more than 80% of their home’s value and nearly 15% more than 90% of the value.
It says that nearly 4% are already a vulnerable position having borrowed more than 100% of what their property is worth.
Especially at risk of finding themselves left without an affordable replacement deal is the 17% who have a history of adverse credit.
But most worrying is the number of people who expect to find themselves in difficulty over the next 12 months.
Brown adds: “These figures shouldn’t be interpreted as scaremongering. Nearly 10% of respondents admitted that they reckon they are at risk of missing mortgage payments in the coming year, with a staggering 22% prepared to consider using other means of credit to meet their mortgage repayments.
“Anyone finding themselves getting into problems with their mortgage payments or other debt are advised to seek help at an early stage. There are a number of organisations that can offer help such as Citizens Advice or The Consumer Credit Counselling Service.
“The worst thing you can do is to bury your head in the sand – seek help and talk to your lender as soon as you feel yourself getting into difficulty.”