A mortgage affordability check looks at your income, regular spending, debts, deposit and credit history to assess whether repayments appear manageable. Lenders may also test your budget against a higher interest rate than the initial deal, to see how you might cope if rates rise. A lower rate can reduce the payment used in the calculation, but it does not guarantee you will pass or be offered a particular loan amount. Criteria vary, so check the lender’s details or speak to a FCA-authorised mortgage adviser for an assessment based on your circumstances.