Which of the following actions is NOT a method to improve a credit score?

Maxing out credit cards represents a practice that is detrimental to one's credit score. This action typically leads to high credit utilization, which is a significant factor that credit scoring models consider when calculating an individual's credit score. High credit utilization suggests to creditors that a borrower is relying heavily on credit, which can indicate financial distress and may lower their score.

In contrast, paying bills on time is crucial as payment history accounts for a large portion of a credit score. Disputing inaccuracies on credit reports helps ensure that the information being reported to credit bureaus is accurate, which can positively impact a credit score. Similarly, maintaining a low credit utilization ratio shows responsible credit management, which can lead to an improved credit score. Thus, maxing out credit cards stands out as the action that does not contribute positively to credit score improvement.