What Is a Credit Score?
A credit score is a three-digit number generated by credit reference agencies (called credit bureaus in the US and Canada) that summarises your borrowing history and predicts how likely you are to repay future debt. Lenders check it every time you apply for a mortgage, loan, credit card, mobile phone contract, or even some rental agreements.
The score is calculated using data in your credit report β a detailed record of every credit account you've opened, every payment made or missed, how much of your available credit you use, and how long you've been borrowing. The better your borrowing history, the higher your score.
Your credit score doesn't just affect whether you get approved β it determines the interest rate you're offered. A borrower with an excellent credit score applying for a mortgage could be offered a rate 0.5β1.5% lower than someone with a poor score. On a Β£250,000 mortgage, that difference can amount to tens of thousands of pounds over the term.
Credit Score Ranges by Country
Scoring systems differ between countries and between agencies within the same country. Here's how the main systems compare:
| Country / Bureau | Score Range | Good Score | Excellent Score |
|---|---|---|---|
| UK β Experian | 0β999 | 881β960 | 961β999 |
| UK β Equifax | 0β1000 | 531β670 | 811β1000 |
| UK β TransUnion | 0β710 | 604β627 | 628β710 |
| US β FICO Score | 300β850 | 670β739 | 800β850 |
| US β VantageScore | 300β850 | 661β780 | 781β850 |
| Canada β Equifax | 300β900 | 660β724 | 760β900 |
| Australia β Equifax | 0β1200 | 622β725 | 833β1200 |
How Is Your Credit Score Calculated?
Credit agencies don't publish their exact formulas, but the main factors are well understood. In the UK, the five key factors (with approximate weightings) are:
Payment History (~35%)
Whether you pay on time, every time. A single missed payment can drop your score by 50β150 points and stays on your file for 6 years. This is the single biggest factor in every credit scoring system globally.
Credit Utilisation (~30%)
How much of your available credit limit you're using. Using more than 30% of your total limit is seen negatively. Staying below 30% β ideally below 10% β shows lenders you're not over-reliant on credit.
Credit History Length (~15%)
How long your accounts have been open. Older accounts show a longer track record of responsible borrowing. Closing old credit card accounts can reduce your average account age and lower your score.
Credit Mix (~10%)
Having a variety of credit types β credit cards, loans, a mortgage β can slightly boost your score. It shows you can manage different kinds of borrowing responsibly. Don't open accounts just for this reason though.
New Credit / Hard Searches (~10%)
Each time you apply for credit, the lender performs a hard search on your file. Multiple applications in a short period can signal financial stress and temporarily reduce your score by 5β20 points per search.
Electoral Roll Registration
Being registered on the electoral roll at your current address is a straightforward way to improve your UK credit score. It helps lenders verify your identity and address. Registration is free and quick via gov.uk.
How to Check Your Credit Score for Free
All three main UK credit bureaus offer free access to your report and score:
- Experian: Free score via CreditMatcher; full report free via the statutory access route or Β£14.99/month for full monitoring.
- Equifax: Free 30-day trial, then Β£7.95/month; free statutory report available.
- TransUnion (via Credit Karma): Free access, no trial required. Updates weekly.
In the US, you're entitled to one free report per year from each bureau via AnnualCreditReport.com. In Canada, check Equifax and TransUnion for free online. In Australia, check via Equifax, Experian, or illion (each free once per year).
Checking your own credit score is a soft search β it has zero impact on your score. Only hard searches (when a lender checks your file for a credit application) affect the score. Check your score as often as you like β monthly monitoring is sensible to catch errors early.
Why Your Credit Score Matters Beyond Borrowing
Many people don't realise a credit score affects more than just loan and mortgage applications:
- Rental applications: Many landlords and letting agents run credit checks on prospective tenants.
- Mobile phone contracts: A 24-month contract is a form of credit and involves a hard search.
- Car finance (PCP/HP): The interest rate offered on car finance deals is directly tied to your credit profile.
- Utility contracts: Some energy suppliers run credit checks before agreeing to supply on credit terms.
- Insurance: In the US, many insurers use credit-based insurance scores to determine premiums. This practice is not permitted in the UK.