If you have defaults or a default against you, you may think you wouldn’t be able to get a mortgage however it is still entirely possible. How likely you are to get approved for a mortgage is dependent on the amount and date of the defaults, the longer ago and fewer there are of these the more likely you are to be approved. If you still have a good history with your current account holder despite the default elsewhere this will help your chances with the lender.
Of course if your default is now over 6 years ago it wont even appear on your credit report for the creditor to see. In most cases a mortgage can be source even despite the defaults but of course the worse they are on your credit report the harder it will be and the higher the rates will be too.