One person. Three files. A lot of scores.

Each month, every card and loan you have tells the bureaus what happened: the balance, the limit, and whether you paid on time. The bureau writes it down. That running record is your credit report, and it holds four kinds of things:

• Accounts. Every card and loan: when it opened, its limit, its balance, and each month’s payment, on time or late.
• Checks. Who looked at your file and when. A check from an application, called a hard inquiry, shows for two years.
• Negatives. Late payments, collections, bankruptcies. Most have to leave after seven years.
• Who you are. Names, addresses, and employers you have used.

What is not on it: your income, your savings, and your score. A score is not stored anywhere. It is calculated the moment someone asks, from whatever the file says that day.

Experian, Equifax, and TransUnion are private companies, and each keeps its own file on you. A lender sends the same update to the bureaus it works with, and each bureau posts it on its own schedule. So on any given day the three files rarely match.

• Some lenders skip a bureau. A small lender may report to only one or two, so an account can sit on one file and be missing from another.
• Each file can be frozen. A freeze stops new lenders from opening your file, so a fraudulent application goes nowhere, and it is free at every bureau. You freeze and unfreeze the three separately, and it does not touch your score or the accounts you already have.
• Each file can be disputed. An account that is not yours, a late mark that is wrong, a balance that never updated: each bureau takes disputes online, has to investigate, usually within 30 days, and must correct or remove what it cannot verify. Catching those is the main reason to read the file at all.
• Each file is free to read. AnnualCreditReport.com gives you every bureau’s report once a week, free, by law. Reports only, no scores.

When a lender asks, a formula reads one file and answers one question: how likely is this person to fall seriously behind in the next two years? The answer is squeezed into a number from 300 to 850. Higher means less likely.

FICO’s formula weighs five things. Paying on time is over a third of it. How much of your limits you use is nearly another third. The rest is how long you have had credit, how recently you asked for more, and whether you have both cards and loans.

Lenders read the number in bands:

Poor 300–579Fair 580–669Good 670–739Very good 740–799Exceptional 800+

Paying a card down shows up within a month or two, because only the latest balance counts. A missed payment costs more than any single good move earns, and stays on the file for seven years.

FICO has released many versions of its formula, and each lender picks one. VantageScore is a rival formula most free apps show. They all read the same file, so they move together, but they never quite agree.

Track FICO^® Score 8. It is what most card and loan decisions use, and it is the one you can see from all three bureaus for free.

These are the three sources the CreditMaxer app points to for the score. No card required, no trial, and checking your own score never lowers it. The reports themselves come from one other place, just below.

Before you compare two numbers, read the label:

• Model. It says FICO^® Score 8, not VantageScore or a bankcard score.
• Bureau. You know which of the three files it was read from.
• Date. The two were pulled close together. Files change all month.