What Actually Affects Your Credit Score (Ranked by Impact)

Credit scores are often treated as mysterious, but the two most widely used scoring models — FICO and VantageScore — rest on a short list of factors. FICO, used in most consumer lending decisions in the US, weights those factors clearly enough that you can rank them by impact and focus your effort where it actually pays.

1. Payment history — about 35% of the score

Whether you pay your bills on time is the single largest factor. A single missed payment reported 30 or more days late can drop a score by 60 to 100+ points and stay on your credit report for up to seven years. The mechanical fix is simple: automate at least the minimum payment on every credit account so you never miss one, then pay more when you can.

Late payments, collections, charge-offs, and bankruptcies all fall under payment history. A clean payment record over several years is the fastest way to build a strong score, and the slowest to accidentally damage.

2. Credit utilisation — about 30% of the score

Utilisation is the percentage of your available credit that you are using. If you have a $10,000 total credit limit across all cards and carry $3,000 in balances, your utilisation is 30%. Lower utilisation improves the score; higher utilisation hurts it, often dramatically above 30% and severely above 70%.

The most effective utilisation tactic is to pay down balances before the statement closing date, not just the due date. The score model typically uses the balance reported on the statement, so a balance paid to near-zero before the statement cuts leaves a low reported utilisation regardless of how the card was used during the month.

3. Length of credit history — about 15% of the score

The scoring model rewards long-standing accounts. It considers the age of your oldest account, the age of your newest account, and the average age across all accounts. This is why closing your oldest credit card is usually a mistake — it can lower your average age of accounts and, over time, remove the account entirely from the score calculation.

4. Credit mix — about 10% of the score

A mix of account types (credit cards, an installment loan such as a car loan, a mortgage) helps modestly. This is a small factor and not worth opening accounts you do not otherwise need — it typically becomes relevant only for borrowers pursuing the highest score tier.

5. New credit — about 10% of the score

Each formal credit application (a "hard inquiry") can lower your score by a few points and stays on your report for two years. Multiple hard inquiries in a short period compound the effect. Rate shopping for a single loan (mortgage, auto, student) is usually treated as a single inquiry if done within a two- to 45-day window, depending on the scoring model.

Where to focus your effort

Two habits produce the majority of possible score improvement. First, never miss a payment — automate it. Second, keep utilisation low, ideally below 10% on each card and overall. Everything else is a rounding adjustment on top of those two habits.