How credit scoring really works in the UK
Quick answer: There is no single 'UK credit score'.
There is no single 'UK credit score'. Each lender uses its own scoring model and looks at the data from one or more of the three credit reference agencies — Experian, Equifax and TransUnion. The scores those agencies show you are educational, not the figures lenders actually see.
Last reviewed:
Primary source: https://www.ico.org.uk/your-data-matters/credit/
What's on your credit file
Each agency holds: your electoral roll registration, current and previous addresses (linked to financial accounts you've held there), open and closed credit accounts with balances and payment history for up to 6 years, defaults, County Court Judgments, IVAs and bankruptcies, hard searches from lenders (visible for 1 year), and financial associations (e.g. a joint mortgage).
What is NOT on your file: salary, savings, criminal convictions (unless they involve financial fraud), council tax (in most cases), or how much you have in your current account.
Why the three agencies show different scores
Lenders choose which agencies to report to and pull from — not all lenders use all three. So one agency's file may show an account that another doesn't.
Each agency also has its own scoring model and scale (e.g. Experian 0–999, Equifax 0–1000, TransUnion 0–710 via Credit Karma). The numbers are not directly comparable.
Lenders do not actually use any of these scores. They run your raw file through their own internal model, with their own thresholds and weights.
What actually helps your file
Register on the electoral roll at your current address. Pay every credit commitment (credit card, loan, mortgage, BNPL where reported, mobile contract) on time — payment history is the biggest single factor.
Keep your credit utilisation low — using less than around 30% of available credit card limits is helpful; under 10% looks even better.
Avoid frequent hard searches. Use 'soft search' eligibility checkers before applying for new credit; they don't affect your file.
Time helps. Old issues drop off after 6 years, and a clean run of payments steadily improves your file.
Checking and correcting your file
You can request a free Statutory Credit Report from each agency under data protection law. Free monitoring services like Credit Karma (TransUnion), ClearScore (Equifax) and Experian's basic plan let you see your data ongoing.
Errors should be raised with the agency, which has 28 days to respond. If they will not change the data you can add a Notice of Correction (up to 200 words) explaining your version of events.
Common questions
- Will checking my own file hurt my score?
- No. Checking your own credit file is a soft search — it is only visible to you and has no effect on what lenders see.
- Do utility bills help?
- Some do. Most mobile phone contracts and energy suppliers report to credit reference agencies. Water bills, broadband and TV streaming services generally do not.
- What about Buy Now Pay Later?
- Major providers (Klarna, Clearpay) have started reporting some products to credit reference agencies as the FCA brings BNPL fully into regulation. Repaying BNPL on time can help; missing payments can hurt.