What does "no pre-set spending limit" mean?
Most charge cards don't have set credit limits that you need to stick to when you use them. Instead, purchases are approved based on factors including your spending patterns, credit score, repayment history and financial information that's available to the provider.
So, as you build up spending and payment history on a charge card, the amount you can spend may also increase, without the need to apply for a credit limit increase.