Processing of addition of interest to principal when monthly repayment is past due
The addition of interest to principal on August 27 is: 20,000 yen × 15% × 31 days / 365 days ≈ 254 yen, and it is added to the outstanding borrowing amount. After the addition of interest to principal, the outstanding borrowing amount becomes 20,000 yen + 254 yen = 20,254 yen.
If the monthly repayment amount is not paid on August 27 and repayment is due on the next monthly repayment date September 27, interest is calculated as follows: 20,200 yen (any amount under 100 yen is rounded down) × 15% × 31 days / 365 days ≈ 257 yen. The 257 yen is added to the outstanding borrowing amount. When the next monthly repayment date comes, the outstanding borrowing amount is: 20,254 yen + 257 yen = 20,511 yen.