In many credit card installment plans, the transaction amount, or a large portion thereof, is initially used to reduce your credit limit.
Key points
The limit is then gradually reduced as you make your payments.
However, this mechanism varies between banks and plans; some offers operate differently.
Before starting an installment plan, inquire about the available limit after the transaction and whether the full amount is reserved or paid in installments.
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.