How Are Credit Scores Calculated in the UK? A Plain-English Explanation
Published 5th of August 2012·Updated 1 April 2026
Reviewed by: Reviewed for accuracy April 2026
Your credit score in the UK is calculated by three credit reference agencies: Experian, Equifax and TransUnion. Each uses its own scoring model, so your score will differ slightly between them. All three assess the same core factors: your payment history, how much of your available credit you are using, the length of your credit history, recent applications for credit and the variety of credit types you hold.
Short Summary
No single credit score exists in the UK. Experian scores from 0 to 999, Equifax from 0 to 1,000 and TransUnion from 0 to 710. Lenders use their own internal criteria and may check one, two or all three agencies before making a decision.
Payment history carries the most weight in your score. One missed payment can drop your score significantly; a consistent record of on-time payments is the single most effective way to build a strong score over time.
You can check your credit report for free through Experian, Equifax, TransUnion, or free services such as Credit Karma (TransUnion data) and ClearScore (Equifax data). Checking your own report does not affect your score.
What are the five factors that affect your credit score?
The five factors below each contribute to your overall score. The percentages are approximate and based on widely published guidance from the credit reference agencies:
| Factor | Approximate weighting | What it measures |
|---|---|---|
| Payment history | 35% | Whether you pay on time, every time |
| Credit utilisation | 30% | How much of your available credit limit you are using |
| Length of credit history | 15% | How long your oldest and newest accounts have been open |
| New credit applications | 10% | How many hard searches have been recorded recently |
| Credit mix | 10% | Whether you have a range of credit types (cards, loans, mortgage) |
How does payment history affect your score?
Payment history is the single biggest factor in your credit score. Every missed or late payment is recorded on your credit file and remains visible for six years. A single missed payment can lower your score by a meaningful amount, particularly if your file was otherwise clean.
The most effective habit you can build is paying at least the minimum payment on every account, every month, by direct debit. Experian recommends setting up direct debits for all credit accounts to remove the risk of forgetting a payment date.
What is credit utilisation and why does it matter?
Credit utilisation is the percentage of your total available credit that you are currently using. If you have credit cards with a combined limit of £5,000 and a total balance of £2,500, your utilisation is 50 per cent.
Most credit reference agencies recommend keeping utilisation below 30 per cent. High utilisation signals to lenders that you are heavily reliant on borrowing, which increases their perception of risk. Paying down balances and requesting modest credit limit increases (without spending more) both lower your utilisation ratio.
Does the length of my credit history matter?
Yes. Credit reference agencies reward a long track record of responsible borrowing. The average age of all your open accounts contributes to your score, which is why closing an old credit card can sometimes lower your score slightly; it removes a long-standing account from your average.
If you are new to credit, building a history takes time. A credit builder credit card, used for small regular purchases and paid off in full each month, is one of the most reliable ways to establish a credit history from scratch. Providers including Capital One, Vanquis and Aqua offer cards designed specifically for this purpose.
How do credit applications affect your score?
Every time you formally apply for credit, the lender carries out a hard search on your credit file. This search is recorded and visible to other lenders for 12 months. Multiple hard searches in a short period suggest financial stress to lenders and can lower your score.
Before applying for a credit card or loan, use an eligibility checker. Most major comparison sites and lenders offer soft search eligibility tools that show your likelihood of acceptance without leaving a mark on your file. Use these to narrow down your options before making a formal application.
What can I do if my credit score is low?
A low score is not permanent. The steps below will improve your score over time:
- Register on the electoral roll at your current address (lenders use this to verify your identity)
- Set up direct debits for all minimum payments to avoid missed payments
- Keep credit utilisation below 30 per cent across all cards
- Avoid making multiple credit applications in a short period
- Check your credit report for errors and dispute anything incorrect with the relevant agency
Experian, Equifax and TransUnion all have formal dispute processes for correcting inaccurate information. If information on your file is wrong, removing it can raise your score immediately.
Frequently Asked Questions
Can I check my own credit score for free in the UK?
Yes. ClearScore provides free access to your Equifax credit report and score. Credit Karma provides free access to your TransUnion data. Experian offers a free basic credit score and a paid subscription for full report access. None of these checks affect your score.
How long does negative information stay on my credit file?
Most negative information, including missed payments, defaults, county court judgments (CCJs) and IVAs, stays on your credit file for six years from the date it was recorded. After six years it is automatically removed, regardless of whether the debt has been repaid.
Does checking my credit score lower it?
No. Checking your own credit report is a soft search and has no impact on your score whatsoever. Only hard searches carried out by lenders when you formally apply for credit are recorded on your file.
Why do I have different scores at different agencies?
Each agency uses its own scoring model, and not all lenders report to all three agencies. This means the data held about you may differ slightly between Experian, Equifax and TransUnion, which leads to different scores. The underlying factors assessed are broadly the same, but the precise calculations differ.
How quickly can I improve my credit score?
Some improvements are immediate: correcting an error on your file or getting added to the electoral roll can raise your score within weeks. Others take longer: building a consistent payment history typically improves a score noticeably within three to six months of responsible behaviour.
Does a partner's credit score affect mine?
Not directly. Your credit files are separate unless you have a financial association, such as a joint mortgage, joint loan or joint bank account. Once a financial link is established, your partner's credit history becomes relevant when lenders assess you, and vice versa.