Interest starts when you withdraw funds from your Credit Line to your Wallet, and only applies to that amount, not your full limit.
Your interest rate (APR) depends on your LTV. The higher your LTV, the higher your rate, and the rate applies to your whole balance. You can see it as Current APR (variable) on your Credit Line.
LTV | APR |
Below 20% | 0% |
20% to below 35% | 5.9% |
35% to below 50% | 9.9% |
50% to below 65% | 16.9% |
65% and above | 21.9% |
These rates apply to new Credit Lines. Your Credit Line keeps the rates shown when you opened it.
Interest is calculated every day on what you owe, using a 360-day year. It's added to your balance at 00:00 UTC, so it compounds. It's charged in the asset you borrowed, and when interest is due, the minimum is 0.01 a day.