The financial category that carries the most weight in determining your credit score, according to Fair Isaac (FICO) and the Consumer Federation of America, is your payment history (whether you pay your bills on time). In the standard FICO scoring model, payment history accounts for about 35% of your credit score, which is the largest single slice compared with other categories such as amounts owed, length of credit history, new credit, and credit mix.

TL;DR: On‑time payments matter more than any other factor when it comes to your credit score.