Yes, your credit limit usage is one of the debt factors that affect your Credit Score.
Key points
iScore includes the percentage of available credit card limits that are used as a factor in calculating your score.
In practice, consistently reaching a large percentage of your limit might give the impression of greater credit pressure than someone who uses less and makes regular payments.
However, don't base your score on a single factor; payment history, length of credit history, and the type and distribution of your facilities all contribute to the evaluation.
The figures, fees and limits in this answer vary by bank and change over time — confirm them with your bank or the official source before acting.