When a sale is created in AccountEdge, the pre-tax amounts for each line are calculated and rounded to the nearest penny, if necessary (we only around to two decimal places).

These line amounts are added up to get the total amount for the sale. Amounts that are taxable for each tax code (in the US there can be only one) are totaled separately.

The tax on that total amount is calculated and rounded to the nearest penny. That tax is the total tax for the sale.

We then distribute this tax across the lines of the sale using the following rules:

1. Each line that is taxed by the same code, except the last line, we calculate the tax on the line using the proportion "total tax on sale”/"total taxable amount" and round it to the nearest penny.
2. For the last line that is taxed by that code, we include all of the tax that has not been allocated to the preceding lines.

The above rules ensure that the total tax on the sale is equal to the sum of the tax amounts charged on each line.

What this means is that if you create a sale in AccountEdge that has multiple lines with the same dollar value - you can have the two lines show different totals including tax. This is correct and should display this way.