How much can I borrow?

Typically lenders will loan a multiple of any income. This can be from 3 x Single or joint income up to about 4 x. Some lenders lend on an “affordability” basis and treat each case on its merits.
As a general guide lenders will try to ensure they lend responsibly although it is also down to the customer to be sure that they can afford the monthly costs associated with taking out a mortgage.