The three UK credit reference agencies
The UK has three major credit reference agencies (CRAs). All three are private, FCA-regulated companies. They are not government bodies. They are commercial businesses that compete with each other for lender contracts and consumer subscriptions, while also sharing data through reciprocal industry schemes.
All three CRAs operate under the Data Protection Act 2018, the FCA Handbook CONC and oversight from the Information Commissioner's Office.
The three CRAs run independent databases populated by lenders who voluntarily share data. Some lenders share with all three, some with two, some with only one. That is why your three credit scores can look different even though the underlying behaviour is the same person.
Scoring scales and bands compared
Each CRA uses its own scale and its own band labels. The numbers are not directly comparable. An 880 on Experian sits in roughly the same place as a 700 on Equifax or a 580 on TransUnion. Here are the current 2026 ranges:
| Band | Experian (0-999) | Equifax (0-1000) | TransUnion (0-710) |
|---|---|---|---|
| Excellent | 961-999 | 811-1000 | 628-710 |
| Very Good | n/a | 671-810 | n/a |
| Good | 881-960 | 531-670 | 604-627 |
| Fair | 721-880 | 439-530 | 566-603 |
| Poor | 561-720 | 0-438 | 551-565 |
| Very Poor | 0-560 | n/a | 0-550 |
| UK average | ~797 | ~653 | ~629 |
Equifax rescaled in 2021
Equifax used to score 0-700 (the same upper bound as TransUnion). In 2021 Equifax rescaled to 0-1000 and added a "Very Good" band. Older guides may still reference the 0-700 scale, this is out of date. The current scale is 0-1000.
Which lenders use which CRA
Lenders choose which CRA(s) to use. Most major UK lenders use Experian or Equifax (sometimes both). TransUnion has a smaller market share but is used by some major lenders for specific products.
| Lender | Primary CRA(s) used |
|---|---|
| Lloyds, Halifax, Bank of Scotland | Experian, TransUnion |
| NatWest, RBS | Experian, TransUnion |
| HSBC, First Direct | Experian, Equifax |
| Barclays | TransUnion (primary) |
| Santander | Experian, Equifax |
| Nationwide | Experian, Equifax |
| Tesco Bank, M&S Bank | Experian |
| Capital One, Vanquis (sub-prime) | Equifax, TransUnion |
| Most BNPL providers | Equifax (from July 2026) |
Lender-CRA relationships change over time. The information above reflects 2026 patterns but is not authoritative for any specific application. If a lender declines you, you can ask which CRA they used so you can check that specific report for issues.
Lenders must disclose which CRA they used
Under the Data Protection Act 2018, if a lender declines you based on credit data, you have the right to know which CRA was used. This lets you check the specific file. Email or write to the lender citing your right to be informed of the source of automated decisions. They must respond within 28 days.
Data-sharing schemes: CAIS, INSIGHT and SHARE
Each CRA runs a reciprocal data-sharing scheme that lenders contribute to. To submit data, a lender must also receive data and must follow strict rules on what they can and cannot do with it. The three schemes are governed by SCOR (the Steering Committee on Reciprocity).
| CRA | Scheme name | Volume |
|---|---|---|
| Experian | CAIS (Credit Account Information Sharing) | ~550 million accounts/month |
| Equifax | INSIGHT | Comparable scale |
| TransUnion | SHARE | Comparable scale |
| Governance | Steering Committee on Reciprocity (SCOR) | |
The three schemes are technically separate but in practice cover similar ground. A lender that contributes to CAIS gets to see CAIS data. Same for INSIGHT and SHARE. Lenders contributing to multiple schemes get a richer view, but each scheme is technically owned by its CRA.
Experian in detail
Experian is the largest UK credit reference agency by market share and data volume. It runs the Experian credit report, the Experian Credit Score (educational), CAIS and a wide range of fraud-prevention tools.
Experian Boost lets you add positive payment data (council tax, streaming subscriptions, savings deposits) from your bank account via Open Banking. Adds an average of +13 points per Experian's data.
Equifax in detail
Equifax is the second-largest UK CRA. Its consumer-facing brand is much weaker than Experian's, but its lender relationships are extensive and its data is widely used.
Equifax suffered a major US data breach in 2017 that affected an estimated 700,000 UK consumers. Both the FCA and ICO have since fined Equifax for the related failings. Operations have since been substantially reformed.
Most UK consumers who want to view their Equifax data use ClearScore, which is the most popular free Equifax-data app. ClearScore is owned independently of Equifax and makes money via product recommendations, the credit report itself remains free.
TransUnion in detail
TransUnion (UK) was previously known as Callcredit before being acquired by US-based TransUnion in 2018. It is the smallest of the three but used by some major UK lenders, notably Barclays.
TransUnion International UK Limited is registered with the FCA under firm reference number 737740. Verify on the FCA Register.
Both Credit Karma and TotallyMoney show your TransUnion data free, no trial required. Useful even if you don't think you need it, given Barclays, NatWest and several specialist lenders use TransUnion as a primary CRA.
How to check all three for free
Every UK adult has the right to view their full credit report from each CRA for free. Multiple free routes exist:
Sign up at experian.co.uk. Free score and monthly updates indefinitely. The full report behind a paywall (£14.99/month after free trial), but free score itself is permanent. Or get the statutory report by post.
Sign up at clearscore.com. Free score and full report from your Equifax data, monthly updates, no trial required. ClearScore makes money from product recommendations.
Sign up at creditkarma.co.uk or totallymoney.com. Both free, no trial. Both show your TransUnion data and monthly updates.
CheckMyFile shows all three CRAs in one report. Free 30-day trial then £14.99/month. Useful for a single-view comparison if you spot inconsistencies between CRAs.
Sign up to all three free apps once
Spend 15 minutes signing up to Experian's free service, ClearScore and Credit Karma. Each is a soft search, no impact on score. After that, you can check any CRA at any time. Useful before applying for credit, taking out a mortgage or any other situation where you want to know what lenders will see.
Which one matters most for you
The honest answer: it depends on which lender you are applying to. Different lenders use different CRAs, so the score that matters varies by application.
Check all three before any major application. Six weeks before is ideal, as that gives time to dispute any errors and see them resolved (~28 day response).
Ask the lender which CRA they used. Most decline letters say. If not, write asking. Then check that specific CRA's report for unrecognised accounts, defaults that should have dropped off, or addresses that do not match.
Most major mortgage lenders use Experian or Equifax. Check both. Mortgage applications are particularly sensitive because the amounts are large and the searches are coordinated, you typically get only one or two attempts before the rejection pattern starts to hurt.
Check all three. The one that matters is the one your lender used.
You don't get to pick which CRA your lender uses. But you can ensure all three are clean, accurate and showing the best possible picture of your credit history. The 15 minutes spent signing up to free apps at all three CRAs is one of the most valuable financial admin tasks you can do. See our companion guides on how UK credit scores work and what is on your credit file for the full picture.