21/07/2026
The UK mortgage affordability system contains one of the strangest loops in personal finance.
You are currently paying £1,350 a month in rent. You have been paying it consistently, on time, for years.
You would like to pay £950 a month on a mortgage instead. That is £400 a month less than you are already demonstrating you can manage without difficulty.
The lender is not sure you can afford it.
The reason you cannot build the deposit that would prove you can is the £1,350 a month in rent.
The reason you are paying £1,350 a month in rent is that you cannot access the mortgage.
The reason you cannot access the mortgage is that you have not built the deposit.
The reason you have not built the deposit is the £1,350 a month in rent.
At no point in this process does anyone observe that you are already paying significantly more than the mortgage would cost and that this is perhaps relevant information.
The system was designed to assess risk.
What it often ends up assessing is whether you are already in a financial position stable enough not to need the mortgage. Which is a different question.
And a considerably less useful one for the people the housing market was theoretically built to serve.
The renters who would make the most reliable mortgage borrowers, the ones demonstrating for years that they can meet a monthly payment larger than the one they're asking for, are the ones the deposit requirement is hardest on.
Because they are already paying the deposit gap to a landlord every month.
The loop is not an oversight. It is the shape of a system that has not been updated for the market it now operates in.
