If you are planning to buy a property then start talking to your mortgage advisor, it can either be done in your bank and they can talk through the products they offer or you can also talk to an independent mortgage advisor, also called a broker who will help you go through a range of products from lenders.
Before mortgage lenders base the amount you could lend from your income, however on 2014 the Financial Conduct Authority reviewed that the amount a lender can borrow is no more than four and a half times from their income. It is also necessary to undergo an affordability assessment to ensure that your expenses met not just your personal and living expenses but also repayment for the lend. You should also make sure that you will be able to pay the mortgage in the future since any changes or late payments can increase the value of your interest.
A deposit is important and plays a large role in assessing your capabilities since this makes the mortgage provider more willing to lend. The higher the deposit the lesser the event that the property falls as a negative equity which means that the value of the house is lesser than the propose amount of the property at the start of the lend.