Credit utilisation is one of the factors that UK credit reference agencies use when calculating credit scores. It measures how much of a person's available revolving credit is currently in use. Despite being widely discussed, the exact way each agency treats utilisation differs, and much of the detail remains undisclosed.
This guide explains what credit utilisation is, how it is calculated, what the known thresholds are, and where common confusion arises — all within the UK context.
Quick Answer (Read This First)
Credit Utilisation Ratio is the percentage of your available revolving credit (e.g., credit cards) you are currently using. It is calculated by dividing Outstanding Balances by Total Credit Limits.
- Formula: (
£500 Balance/£1,000 Limit) = 50% Utilisation. - Scope: Applies to revolving credit only (Credit Cards, Overdrafts). It does not include instalment loans like mortgages.
All three UK agencies (Experian, Equifax, TransUnion) factor this into their scores. There is no universal published UK percentage weighting. VantageScore percentages from the US do not establish how a UK TransUnion score works.
IMPORTANT
The "Goldilocks" Zone: While keeping utilisation low is good, 0% is not always optimal. Lenders want to see active, responsible usage. Conversely, utilisation above 75-90% sends strong negative signals of financial stress.
How the System Works
Credit card issuers report your balance and limit to CRAs typically once per month, usually around your statement date.
- Snapshot Timing: The balance reported is the one on that specific day. even if you pay it off in full 2 days later, the "Snapshot" has already been sent to the CRA.
- Scoring Models: Each CRA has its own secret recipe.
- TransUnion: UK weighting is model-specific; do not import US VantageScore percentages.
- Experian/Equifax: Undisclosed weightings, but significant.
- Data Consistency: Not all lenders report to all three agencies, so your utilisation figure might differ between your Experian, Equifax, and TransUnion reports.
Key Rules, Thresholds, and Timelines
While there is no "Legal Limit" for utilisation, suggested percentages are guidelines rather than universal scoring thresholds.
The 30% Threshold
Experian UK suggests keeping credit utilisation below 30% where practical. This figure is not a legal limit or a guaranteed approval threshold.
- Impact: Analysis suggests keeping balances under 30% can be associated with a healthy score boost.
- Scope: There is no global rule requiring lenders to classify every balance below 30% as low risk.
The 50–75% "Amber Zone"
Utilisation between 50% and 75% is widely regarded as a warning sign.
- Signalling: It suggests you are becoming reliant on credit.
- Interpretation: Do not treat 50% as a verified universal Equifax cut-off; the model and the rest of the file matter.
Above 90% (Red Flag)
Using nearly all your available credit is a major negative indicator.
- Impact: Can lower a score, but no fixed points deduction applies across UK agencies and model versions.
- Risk: Lenders view this as "maxed out" and high risk for default.
The 0% Dilemma
Why is 0% not perfect?
- Lender Logic: If you never use your credit, there is no evidence that you can manage debt responsibly.
- Strategy: If you already use a card, pay on time and avoid unnecessary balances. Do not borrow or pay interest just to manufacture a utilisation percentage.
Common Points of Confusion
"Paper" Losses vs Real Debt
If you pay your card in full every month, you report 0 debt to yourself, but the CRA might see a balance.
- Reason: If your statement generates on the 1st with £500, and you pay it on the 25th, the CRA sees the £500 snapshot from the 1st.
- Fix: To show 0% (or very low), consider paying off the balance before the statement date.
Total Limit Myths
"A higher limit is always better" isn't strictly true.
- Yes, it lowers your percentage (e.g., £500 balance on £10k limit is only 5%).
- BUT: Lenders also assess "Total Available Credit". If you have access to £50,000 unsecured credit, some lenders may worry you could get into debt instantly, posing an affordability risk.
Instalment Loans
Your mortgage balance or car finance does NOT count towards your credit utilisation percentage. Those are separate assessment categories.
Important Exceptions
- Overdrafts: Experian analysis suggests some overdrafts aren't counted in the standard "Utilisation %" metric, though they are "Unsecured Debt". This varies by agency.
- Closed Accounts: Closing an old, unused card removes its credit limit from your total.
- Example: You have £2k debt on £10k total limit (20%). You close a £5k limit card. New total limit is £5k. Utilisation jumps to 40%.
- Inactive Closure: Issuers may close unused cards under their terms. There is no universal 12-month deadline.
What This Means in Practice
- Check the Snapshot: Don't stress about the daily balance. Reported balances matter for scoring; daily balances still matter for interest, payments and your own cashflow.
- Aim for <30%: Use a low utilisation level as a budgeting aim, not a set of hard underwriting limits.
- Don't Fear Usage: Using a card for groceries and paying it off shows better management than a dusty card in a drawer.
FAQ
For more details on improving your rating, visit our Credit Scores Hub or read about How to Get Your Statutory Credit Report.
Sources and Further Reading
This guide is based on UK primary legislation, regulator handbooks, and official guidance. The following sources cover the rules described above:
Free, impartial debt advice is available from MoneyHelper, StepChange, and Citizens Advice.
