In PERIFACT, the so-called banker's method can be applied. What is that actually? Here, numbers are rounded to the 3rd decimal place. In other words, half cents.
Example
Suppose; A product costs 3828.50 euros euro excluding 21% VAT.
So, including VAT, that's 3828.50 * 1.21 = 4632.485 euros
Using the banker's method, some round off that amount to 4632.49 euros.
Chicken - egg
PERIFACT offers a unique functionality that allows you to manage the final amount can be adjusted manually. The program then automatically calculates the unit price based on the quantity entered and the adjusted final amount. This is particularly useful when you want to achieve a "round" final amount, for example.
The problem is that if you use the banker's method AND you allow the final amount to be adjusted manually, inconsistencies may arise (due to rounding again in the unit price). This is a chicken-and-egg situation. This is why PERIFACT has built in a restriction:
If the banker method is enabled, the final amount cannot be entered manually.
This is a logical choice because the banking method follows a specific rounding logic. By manually adjusting the final amount, you would break this logic, which could lead to unexpected results.
PRECISION
Want to adjust the precision (read:number of decimal places). Then look here.