Austrian 20% VAT rounding with 9.99 price


I’m working for a client on an automatic invoicing system.

This client has a product priced 9.99 and different VATs based on the user location (Germany, Austria, Switzerland, etc).

I think there is an error in the rounding. When the third digit after comma is a 5, as in the Austria case, this is the result:

The total price is 9.99
The net price is 8.325 (9.99/1.20)
So the VAT is 1.665

If you do 8.325 x 1.20 = 9.99, no roundings

In Invoice Ninja
The amounts shows though are:
Unit cost (passed from API) 8.325
Line total 8.32
Subtotal 8.33
Tax 1.67
Total 10.00
Amount due 0.01

I tried to force the right amount putting a unit cost of 8.3249, but it doesn’t work: the difference between the total and the paid goes from -0.01 (8.3249) to +0.1 (8.325), when mathematically the latter should be 0.00 (9.99 total).

If I create a custom rate of 19.999%, it works, but the wrong rate is shown all over the invoice.

Can you please look into it? Otherwise my client will be forced to choose another tool because of the incorrect fiscal information in their invoices.


If you’re using the hosted version it may be better to enable company level inclusive taxes. Note: this can only be enabled in an empty company. If you’re self hosting you may want to try the v5 beta.