If I remember correctly the calculation of interest rate has been changed to be daily compounded for the 2015 version.

Sage 50 is now using the daily rate, which is fine; however, it is not actually calculating the interest using that daily rate. As mentioned above, the statement is showing the appropriate daily rate; however, the actual interest calculated is wrong by a factor of approximately 8.7.

Sage 50 is now using the daily rate, which is fine; however, it is not actually calculating the interest using that daily rate. As mentioned above, the statement is showing the appropriate daily rate; however, the actual interest calculated is wrong by a factor of approximately 8.7.

The daily compounding rate will be lower than the daily straight rate. 12% / 365 is 0.0328%, but if the total compounded annual rate is supposed to be 12%, the daily rate must be lower or it will exceed the 12%. If I set my annual rate to 12%, I show a daily rate of 0.0311% on both the setup screen and the statement.

As for the incorrect calculation on the statement - how overdue is the $10190.67? Just one month? If so, then yes the interest would be 10190.67*12/365*30 days = 100.51, but if the amount is overdue by several months you need to increase the number of days in the formula accordingly. If the amount is overdue by 8-1/2 months, the $869 is reasonable.

However, that all said, I did my own calculation using the sample database on Mainline Rail Ltd. As of Mar 31/15 it has an invoice from Oct 10/14 still owing $12,988.38, with 60 day payment terms. I ran a statement using 12% annual and the statement calculated $334.93 interest. No matter how I do the math, I consistently come up with interest higher than that. If I use the full 111 days, I calculate interest at 448 using the daily rate, or $456 actually compounding the interest at 12% annually. If I use 90 days, I get $363 daily or $368 compounding. Where does the $334 come from? Maybe my compounding math is wrong, but I can't see how I could be out by that much.