How do my credit limits impact my score?
It may be a personal choice, but a low credit limit can suggest to lenders that you're less comfortable with higher limits and not making larger repayments on time.
Using most, or all, of the available credit may also negatively impact your credit score as it can indicate that you are financially stretched, even if your limit is quite low. If you want to keep your score high and your credit report in good shape, you should try to use less than 50% of your available credit limit.