Which of the following is NOT a valid method of improving your credit score?

The method of keeping credit cards for 2-3 years and then canceling them is not a valid way to improve your credit score because canceling credit cards can negatively impact your credit history. A significant factor in credit scoring models is the length of your credit history. When you cancel a credit card, you reduce the average age of your accounts, which can lower your score. Additionally, the total available credit decreases, potentially increasing your credit utilization ratio if you carry balances on other cards.

In contrast, paying bills on time is known to have a positive impact on your credit score, as it demonstrates responsible credit behavior. Reducing overall debt load is also beneficial, as it decreases your credit utilization ratio, which is another key component of your score. Lastly, maintaining a mix of credit types, such as credit cards, auto loans, and mortgages, can enhance your credit profile, showing that you can manage various credit forms responsibly.