UK Credit Utilisation: How It Affects Your Score

Credit utilisation is the percentage of available credit a borrower is using at the moment the credit file is updated. Across all three UK credit reference agencies it is one of the largest factors in credit scoring, alongside payment history. Even borrowers who pay their cards off in full each month can score lower than expected if their cards report high mid-month balances to the CRAs.

This guide covers what counts in utilisation, the optimal range, the timing mechanics, and the practical actions to manage utilisation across multiple cards.

What credit utilisation means and how it's calculated

Utilisation = (current balance) / (credit limit). For a card with GBP 5,000 limit and GBP 1,500 balance, utilisation is 30%. The figure is reported to the CRAs typically on the card's statement date each month. The reported figure is what shows on the credit file until the next statement, regardless of subsequent payments or spending.

Aggregate utilisation across multiple cards is also tracked. A borrower with three cards totalling GBP 15,000 of limit and GBP 4,500 of combined balance has aggregate utilisation of 30%. The individual card utilisations and the aggregate both feed into scoring.

Utilisation does not include mortgages, personal loans, or other fixed-payment credit. Those are scored separately on different criteria (payment history, term remaining, original balance). Utilisation specifically captures revolving credit - cards, overdrafts (where the bank reports them as credit accounts), and similar products.

Worked example: a borrower has GBP 8,000 of card limits and uses around GBP 2,000 a month, paying in full at statement date. The CRA sees the statement-date balance of GBP 2,000 = 25% utilisation. Even though they pay in full, the score reflects the snapshot utilisation, not the cleared balance.

The 30% rule and what 'optimal' means

The common rule of thumb is to keep utilisation below 30% of available credit. This is supported by the three CRAs' scorecard weighting: utilisation in the 0-30% range typically does not significantly drag the score; utilisation 30-50% has a moderate drag; above 50% has a more material drag; above 70% can be a significant negative factor.

Optimal (highest-scoring) utilisation is in the 1-10% range, not 0%. Showing some utilisation (1-10%) demonstrates the borrower is actively using credit and managing it responsibly. Zero utilisation across all cards may produce a slightly lower score than 5% utilisation because lenders cannot see active management behaviour.

The 'rule' is a guideline, not a hard threshold. A single month of 50% utilisation followed by months of low utilisation has minimal lasting impact. Sustained high utilisation over months or years is the concerning pattern.

Practical action: where a borrower expects a large card transaction (a holiday, a home appliance), paying off the card mid-month before the statement date keeps the reported utilisation low. The transaction is paid for; the credit file does not see the temporary spike.

Timing: statement date versus payment date

Most cards report balance to CRAs on the statement date. The statement date is typically 21 days before the payment due date. A card with statement date on the 15th of each month and payment due on the 5th of the next month reports the statement-date balance, not the post-payment balance.

A borrower who runs the card up to GBP 4,000 between the 16th and the 14th of the next month, pays GBP 3,500 on the 4th, has a statement-date balance of GBP 4,000 (high utilisation reported) even though the payment cleared most of it. The CRA sees the snapshot.

To manage this, paying part of the balance before the statement date reduces the reported balance. A borrower expecting GBP 4,000 of mid-cycle spending could pay GBP 2,500 a few days before the statement date, leaving GBP 1,500 reported as the statement balance (30% on a GBP 5,000 limit instead of 80%).

Worked example: a borrower applying for a mortgage in 3 months runs their cards to GBP 6,000 in February. Statement date 25 February reports GBP 6,000. Mortgage application in April pulls the CRA reports - the February balance is no longer the latest but recent months still show. Paying down before each February-March-April statement date keeps the reported utilisation manageable.

Closing cards and the impact on utilisation

Closing an unused credit card removes the limit from the total available credit, raising the utilisation ratio on remaining cards. A borrower with three cards totalling GBP 10,000 limit and GBP 3,000 balance (30% utilisation) who closes a GBP 4,000-limit unused card now has GBP 6,000 of limit and the same GBP 3,000 balance - 50% utilisation.

The impact varies. Where the closed card was old (long credit history) the impact on length-of-credit-history scoring is also negative. Where the closed card was new and had a small limit, the impact is minor.

Some borrowers close unused cards for security reasons (fraud risk) or simplicity. The score impact is typically manageable but worth knowing. Keeping unused old cards open with small periodic transactions (a monthly subscription) preserves the credit history and limit without active card use.

Edge case: a borrower with a card whose terms have changed unfavourably (annual fee introduced, balance transfer offer ended) may choose to close. The score impact is real but typically smaller than the cost of paying the fee. Comparing the saved fees to the temporary score drop helps decide.

Practical management across multiple cards

The simplest pattern: each card is set up with a direct debit for the full statement balance. The card is used for everyday spending up to a comfortable level. The statement date balance is the typical monthly spend; utilisation is whatever this works out to as a percentage of the limit.

For borrowers near a major application (mortgage, large loan), preparation involves bringing utilisation down across all cards in the 6 months before the application. Paying down or paying off balances a few days before each statement date keeps reported utilisation low. The pattern shows up at all three CRAs through subsequent monthly reports.

For borrowers using one card heavily and others rarely, the heavy card's utilisation matters more than the aggregate. Spreading spending across cards lowers individual-card utilisation; some borrowers maintain three or four active cards each at 10-20% utilisation rather than one card at 50%.

Practical action: an annual review of all credit cards (limits, balances, statement dates, fees) catches issues before they affect scores. The CRA reports show what is being reported and when, allowing the borrower to align spending and payment patterns with optimal reporting.

Utilisation on overdrafts and how it shows

Bank overdrafts increasingly appear on credit reports under FCA changes from 2018 onwards. The overdraft limit is treated as available credit; the used portion is treated as utilisation. A GBP 1,000 arranged overdraft running at GBP 500 average usage shows 50% utilisation - high by credit scoring standards.

This catches some borrowers by surprise. Routine moderate use of a current account overdraft (say GBP 400 across the month before payday) can produce reported utilisation of 40-80% on the overdraft line. Combined with card balances, aggregate utilisation can look high even where the borrower considers their finances managed.

Managing this: paying the salary into the current account each month and clearing the overdraft for at least a few days each cycle resets the reported balance to zero or low for those days. Some banks report end-of-statement-cycle position; others report mid-month snapshots. Knowing the bank's reporting pattern allows the borrower to time payments to optimise the reported utilisation.

Worked example: a borrower has a GBP 800 arranged overdraft averaging GBP 600 of use. Reported utilisation 75% - bad for scoring. Restructuring to have GBP 600 of savings buffer in the account, drawing only briefly into overdraft for end-of-month timing differences, brings reported utilisation under 25%.

Frequently asked questions

What is credit utilisation?

The percentage of available credit being used at the time the credit file is updated. Calculated as balance divided by limit. Aggregate utilisation across all credit cards is also tracked. Around 25-30% weight in credit scoring across the three UK CRAs. Optimal range 1-10%; 30% is the common-sense upper guideline for healthy scoring.

Does paying my card in full keep utilisation low?

Only if the payment lands before the statement date. Most cards report the statement-date balance to the CRAs, not the post-payment balance. Paying after the statement date but before the payment due date avoids late fees but does not change the reported utilisation. To minimise reported utilisation, paying before the statement date is the key step.

Should I close cards I don't use?

Generally no for utilisation reasons. Closing removes the limit from total available credit, raising utilisation on remaining cards. Closing old cards also shortens the average credit history. Keeping unused old cards open (with a small periodic transaction to keep them active) typically helps score. Closing is appropriate where the card has unfavourable terms (annual fee, high APR) and the score impact is acceptable.

How long does it take for lower utilisation to improve my score?

Visible within 1-2 months as the next reporting cycles show the lower utilisation. Significant score improvements (50-100+ points) from bringing high sustained utilisation down to under 30% can take 3-6 months as the CRAs see consistent low-utilisation reporting. The CRA scoring models weight recent activity heavily, so improvements show up faster than negative changes typically come off.

Does utilisation matter for mortgages?

Yes. Mortgage underwriters check credit reports including utilisation. High utilisation (above 50%) on cards typically reduces the affordability assessment because it suggests revolving debt and potential financial stress. Bringing utilisation down across all cards in the 6 months before a mortgage application is standard practice. Mortgage itself is not counted in utilisation; only revolving credit (cards, overdrafts) is.