If you have bad credit you will not only have a hard time getting a loan, but you will be charged a higher APR. As a result, your mortgage payment will be higher than if you had good credit. If you already have a home mortgage, having bad credit will not affect it. If you have bad credit and go to get a mortgage, you run a risk of being denied a loan until bad debts are taken care of and even then you may have a higher rate.