Guide · 5 minute read · Updated 10 Jul 2026

How does a UK credit score actually work?

There is no single, official UK credit score that every lender looks up. Three separate agencies hold three separate files on you, each shows you a different number, and lenders largely ignore all of them in favour of their own private scoring. Understanding that is the key to not chasing the wrong target.

Three agencies, three files

The UK has three credit reference agencies: Experian, Equifax and TransUnion. Lenders report your accounts to some or all of them, but not always the same ones, so your three files can genuinely differ. A card that reports only to Experian will not show on your TransUnion file at all.

Each agency also runs its own scoring model on its own scale. Experian scores out of 999, Equifax out of 1,000, TransUnion out of 710. A "700" therefore means very different things depending on who is showing it, which is why comparing the raw numbers across agencies is meaningless. What matters is the underlying file and the band (poor, fair, good, excellent) it falls into.

The number you see is not the number lenders use

Here is the part that surprises people. When you apply for a mortgage or a card, the lender does not pull the tidy three-digit score you see in an app. They take the raw data from your file and run it through their own scorecard, built around who they want as a customer and what they have learned from their own borrowers. They also factor in things the agencies never see, such as your income and how you have behaved on accounts you already hold with them.

That is why two lenders can look at the identical file and reach opposite decisions, and why a friend with a "worse" score than yours gets approved where you were declined. The consumer score is a useful directional guide to whether your file is healthy. It is not a passport that guarantees anything.

What is actually on your file

Your file is a record of how you have handled borrowing, not your wealth. It typically holds your name, date of birth and address history, your electoral roll registration, every credit account (cards, loans, mortgages, overdrafts, some phone and utility contracts) with its balance and payment record, any defaults, County Court Judgments, or insolvencies, and a list of searches. It does not hold your salary, your savings, your job, your ethnicity, or whether you have ever been in your overdraft for a day. Missed payments and defaults stay for six years; then they drop off automatically.

Soft searches versus hard searches

Every time your file is looked at, a search is recorded, and the type matters. A soft search (checking your own report, an eligibility check, an employer's ID check) is visible only to you and never affects anything. A hard search is left when you formally apply for credit, is visible to other lenders, and can slightly lower your score for a few months. A cluster of hard searches in a short window reads as someone desperate for credit, so use eligibility checkers first and space out real applications. If you want to move your file in the right direction, our guide on how to improve your credit score covers the levers that work.

Common questions

Is there one official UK credit score?

No. There is no single national score. Three agencies (Experian, Equifax and TransUnion) each hold a separate file and show a different number on a different scale, and lenders mostly ignore those numbers and use their own private scorecards on the raw file data.

Why is my Experian score different from my Equifax score?

Two reasons. Different lenders report to different agencies, so the underlying files are not identical, and each agency scores on its own scale (Experian out of 999, Equifax out of 1,000, TransUnion out of 710). Comparing the raw numbers across agencies tells you nothing useful.

Do soft searches affect my credit score?

No. Soft searches, such as checking your own report or running an eligibility check, are visible only to you and have no effect. Only hard searches, left when you formally apply for credit, are visible to lenders and can slightly lower your score for a few months.

How long does information stay on my credit file?

Most account and search data stays for around six years. Missed payments, defaults, County Court Judgments and bankruptcies all drop off six years after they occur or are settled, after which lenders no longer see them.

Guidance and education, not regulated financial advice.