Lenders use many factors to determine your eligibility to take out a mortgage. One of the biggest is your credit history: your credit score, your debt-to-income ratio (i.e. how much you owe on credit cards and any other loans vs. how much you earn), any missing or late payments, and so forth. Other factors include the amount of your down payment, how long you've had steady employment, and the purchase price of the home you want to buy.