The credit system feels designed to be confusing — three bureaus, two main scoring models, dozens of versions, and rules that lenders rarely explain. The underlying mechanics, though, are simpler than they look. Here is the whole thing in one article.
Three Bureaus, Same Job
Experian, Equifax, and TransUnion are the three major credit bureaus in the US. They are private companies that maintain records of your credit accounts, balances, and payment history. Each bureau receives reports from lenders and compiles a separate credit report.
Your three reports may differ slightly because not every lender reports to all three bureaus. This is why your score can vary across pulls.
FICO and VantageScore
FICO is the dominant scoring model — used in 90% of US lending decisions. VantageScore is the competitor model, used heavily by free credit-monitoring apps. They use similar factors but weigh them differently.
FICO has many versions (FICO 8, FICO 9, FICO 10, mortgage-specific FICO 2/4/5). For most consumer credit decisions, FICO 8 is the version that matters.
The Five Factors
| Factor | FICO Weight | What It Means |
|---|---|---|
| Payment history | 35% | Are you paying on time? Late 30+ days hurts a lot. |
| Amounts owed | 30% | Utilization. Under 30% is good, under 10% is great. |
| Length of history | 15% | Average age of accounts. Older = better. |
| Credit mix | 10% | Mix of revolving (cards) and installment (loans). |
| New credit | 10% | Recent applications. Hard inquiries fade in 12 months. |
Hard vs Soft Inquiries
A hard inquiry happens when you apply for credit — it temporarily drops your score by 2–5 points and stays on your report for 24 months. A soft inquiry (checking your own score, pre-approved offers, monitoring services) does not affect your score.
The credit system is opaque but not magical. Pay on time. Keep utilization low. Do not open new accounts unnecessarily. Wait. That is 90% of credit optimization. The other 10% is nuance worth knowing — but it only matters once the basics are solid.
