Borrowers using the Help to Buy mortgage indemnity guarantee scheme must be using less than four-and-half times their income to support the application.

For all applications, Santander’s online affordability calculator will now display a single maximum loan amount rather than different amounts for low, medium and high credit scores.

To coincide with this change the lender will be updating its Office of National Statistics data which it uses to verify a clients’ stated expenditure.

Applicants taking out an interest-only mortgage will need to have £150,000 equity in their property where the sale of the property is their exit strategy.

In a broker alert the lender said: “As a responsible lender we want to ensure that customers have sufficient equity in their property to enable them to sell and downsize at the end of the mortgage term.”

The maximum age of interest-only or part-and-part borrowers has now been restricted to 65 on maturity of the mortgage.

The maximum mortgage term for the Help to Buy equity loan scheme has been increased from 25 to 35 years.

The maximum loan-to-value for new build flats has been increased from 75% to 80%.

The changes take effect from Friday 25 July this week.