For most joint mortgages, you will need a mortgage deposit of 10% of the purchase price of the property. However, there are some lenders who will accept a 5% deposit if your financial circumstances mean you can’t afford to pay more. But as you will be applying for a joint mortgage with a partner, friends, or family members, you may be able to access a better mortgage deal with a lower interest rate if you can combine your joint incomes for the deposit.