The types of fees you pay will depend on your line of credit. One commonality however is that all lines of credit will start accumulating interest from the moment you withdraw funds.
This interest is calculated daily, from the first day you use your line of credit, and you’ll be charged until the balance is paid off in full. Therefore, it's best to start paying off your balance as soon as you can.
Some lines of credit, such as the Home Equity Line of Credit and the Personal Flex Line®, also have service charges. The Personal Flex Line also has fees for certain transactions that you can pay on a per-transaction basis or with a fixed-cost package.