There are a number of reasons why someone may have a negative credit history. These include missed payments, defaulting on loans or credit cards, having too many credit accounts open at once, or being declared bankrupt. Additionally, having a County Court Judgment (CCJ) on your record can also negatively impact your credit score. It is important to check your credit report regularly to ensure that any information it contains is accurate and up-to-date. If you find any errors, it is important to contact the relevant lender or creditor to have them corrected as soon as possible in order to maintain a good credit score.