Answer:
The factor that has the biggest impact on a credit score is payment history. This typically makes up around 35% of your FICO score, which is one of the most common credit scoring models used in the USA [FICO score ON myFICO myfico.com].
Payment history refers to your track record of paying bills on time. This includes things like credit card payments, loan payments, rent payments, and any other debts you may have. Making consistent on-time payments shows lenders that you are a responsible borrower and are likely to repay your debts in the future. Conversely, late payments, missed payments, or accounts sent to collections can significantly lower your credit score.