What is Utilisation Rate?
The percentage of your available credit that you're currently using. For example, if you have a £5,000 credit limit and a £2,500 balance, your utilisation is 50%. Keeping utilisation below 30% is generally good for your credit score. When stoozing, high utilisation on one card is normal but may temporarily affect your score.
Credit utilisation is the share of available credit currently in use, measured both per card and across all cards combined. A £2,500 balance on a £5,000 limit is 50% utilisation on that card; the overall figure divides total balances by total limits. Credit reference agencies see the balances lenders report each month, so utilisation is effectively a monthly snapshot.
Scoring models treat high utilisation as a sign of credit stress, and figures below roughly 30% are generally read favourably. The effect is not a lasting mark, though: unlike a missed payment, utilisation carries no memory — the score component recovers as soon as reported balances fall.
Stoozing runs against this deliberately. A stooze card sits at or near its limit for the length of the 0% deal, which pushes utilisation up and can trim a credit score for the duration. Overall utilisation across all cards softens the per-card effect, and the score recovers once the stooze is repaid.