Credit Scores Explained: What They Are, Why They Matter, and How to Build Yours

Your credit score is a three-digit number that tells lenders how likely you are to pay back money you borrow. That number follows you. It affects whether you get approved for an apartment, a car loan, or a mortgage, and at what interest rate. A high score saves you real money over a lifetime. A low score costs you real money, often in the form of higher interest rates on debt you were going to take on anyway.

The score ranges from 300 to 850. Anything above 740 is generally considered excellent. My score has always been in the 800s. Here is how it works and how to build it from nothing.

What goes into your score

The FICO score, which is the most widely used model, is calculated from five factors. Two of them account for the majority of your score, and they are both things you have direct control over.

The two rules that cover 65% of your score

Pay on time, every time. A single missed payment can drop your score significantly and stay on your report for years. Set up autopay on every account. Not the minimum payment. The full balance. More on why in a moment.

Keep your utilization low. Credit utilization is the percentage of your available credit that you are using. If your combined credit limit across all cards is $10,000 and you have $3,000 charged, your utilization is 30%. The general guidance is to keep it below 30%, and lower is better. I keep mine well under that by requesting credit limit increases whenever my income grows. A higher limit with the same spending means lower utilization.

How to start building credit from zero

If you have no credit history, you cannot borrow based on a score that does not exist yet. There are two common ways to start. The first is a secured credit card. You deposit a sum of money, often $200 to $500, as collateral, and that becomes your credit limit. You use the card for small purchases, pay the balance in full every month, and after 12 months or so you will have a meaningful credit history. My wife used this approach when she was starting out.

The second is having someone with good credit cosign on a loan with you. When I was starting out, my father cosigned on a car loan. Making payments on time built my credit history. The cosigner takes on risk if you do not pay, so this is a favor that comes with real responsibility on your end.

A third option is becoming an authorized user on a parent or family member's credit card. You get a card attached to their account, and their history on that card may appear on your credit report, giving you a head start. The word "may" matters here: not all lenders report authorized user accounts, and some credit scoring models weight them less than primary account history. This option can help, but it is less reliable than the secured card or cosigned loan routes. If it is an option for you, take it — just do not count on it as your only strategy.

As you get established: keep increasing your limits

Once you have a few cards open and your income is growing, request credit limit increases regularly. Most issuers will approve an increase once per year if you ask. Before requesting, call or check online to confirm whether the issuer does a soft pull or a hard pull for limit increase requests. A soft pull has no impact on your score. A hard pull temporarily dings it by a few points. Most major issuers use soft pulls for existing customers, but it varies. When in doubt, ask before you request. A higher limit is not an invitation to spend more. It is a tool for maintaining a good score.