How does the FICO scoring model work?

FICO is the most widely used credit scoring model in the U.S. Scores range from 300 to 850; most lenders consider 670 and above "good" and 740+ "very good." The model weighs five factors, and understanding their weights tells you exactly where to put your effort.

Factor Weight What it measures
Payment history35%Did you pay on time? Every account, every month.
Amounts owed (utilization)30%What % of your available credit are you using?
Length of credit history15%How old are your accounts on average?
Credit mix10%Do you have both revolving (cards) and installment (loans) accounts?
New credit (inquiries)10%How many new accounts or hard pulls in the past year?

The big insight: the first two factors — payment history and utilization — control 65% of your score. Get those right, and the rest follows naturally over time.

What helps your credit score vs. what hurts it?

Action Effect on score Notes
Pay on time every monthBuilds (+)Single most powerful positive action
Keep utilization below 10%Builds (+)Optimal; below 30% is also good
Keep accounts openBuilds (+)Older accounts increase average account age
Open a second account after 12 monthsBuilds (+)Adds credit mix; spaces out inquiries
Enroll in rent reportingBuilds (+)Gets rent payments counted in your file
Missing a paymentHurts (−)Drops score 60–110 pts; stays 7 years
Maxing out a cardHurts (−)100% utilization can drop score 40–60 pts
Closing old cardsHurts (−)Reduces average account age and available credit
Applying for many cards at onceHurts (−)Multiple hard inquiries signal risk

Your step-by-step credit-building plan with an ITIN

Follow this sequence. Each phase builds the foundation for the next one.

  1. Month 1–2: Open a secured credit card. Apply at an ITIN-friendly issuer — ideally a credit union or a fintech with an explicit ITIN program. Put down the minimum deposit ($200–$300). See secured credit cards for ITIN holders.
  2. Month 1–6: Build a perfect payment record. Charge one small purchase each month — a coffee, a subscription. Pay the full balance before the due date every month. Do not carry a balance.
  3. Month 6: Check your credit score. After six months of reporting activity, a FICO score should exist. Use the free score your issuer provides (many do), or request a free report from AnnualCreditReport.com.
  4. Month 12–18: Request a graduation or open a second account. Ask your secured card issuer about upgrading to an unsecured card. Alternatively, if your score is 630+, apply for a starter unsecured card at the same or another ITIN-friendly issuer. See unsecured credit cards with an ITIN.
  5. Month 12–24: Keep utilization low as limits grow. As your credit limit increases, keep your balances proportionally low. A $1,000 limit with a $90 balance is excellent (9% utilization).
  6. Month 24+: Explore rewards cards. With a score above 670, many issuers with cash-back and travel rewards programs will approve you. Continue the same disciplined habits. Never carry a balance just to look active.

Does an ITIN limit your credit-building options?

An ITIN is a fully functional tax ID for credit purposes. The credit bureaus (Equifax, Experian, and TransUnion) build credit files using your name, date of birth, and address — not your SSN or ITIN directly. What an ITIN does affect is which issuers will approve you, since some have systems that only accept SSNs. Once you're in the door with an ITIN-friendly issuer, the actual credit-building mechanics are identical to those for any U.S. resident.

See also: complete ITIN credit card guide · which issuers accept an ITIN · find your card now.