California Company Setup Guide:
Here is the link to APR Calculations and Common Percentages
From discussions with multiple operators in California, we understand that cash advances in California are done on a flat rate basis, with a maximum interest/fee of 15% of the principal amount regardless of loan length, which cannot exceed 30 days. This means that you should not allow the program to charge additional interest if a cash advance is paid late. It is our understanding that some California operators reduce interest for early payments, and some do not. We assume this is a matter of choice, and that there is no rule prohibiting such discounts, but we recommend that you check with the state of California to verify this.