Some years ago one of my daughters went to her bank for a small loan (to purchase a car). She had been with this bank for decades, had her NHS salary paid into this monthly, her mortgage payments came from it and she had never been overdrawn. Loan was refused.
Reason, her partner, with whom she had not been for several years, had originally been on the joint mortgage - Seven years earlier he had been bought out - all carried out properly with appropriat paperwork. However, prior to that he had been 'borrowing' sums of money against the house. She knew that and had needed to deal with those coming round trying to collect those debts.
She had not at the same time sorted our the credit rating on the house. So - she then found out that although she had NEVER had a debt, the house had a bad credit rating due to his debts all k those years earlier.