Tax amount + subtotal not equal total amount

Hi there!

I found an issue with rounding the numbers: then I create an invoice I need to specify tax_rate1, but the sum of subtotal and tax value in different with 1 cent:
The real total is 9.9EUR.

How to fix this? Maybe there’s a way to specify tax amount and tax percentage so we calculate it on our side?


I’m not sure I follow, 8.31 * 1.19 = 9.8889 which rounds to 9.89.

That’s exactly the problem:
The total amount we have - is 9.9, after we calculate the tax amount on our side 19% -
9.9 EUR in cents is 990, so the subtotal will be 990 / (19 / 100 + 1) = 1.9 + 1 = 831.9327 - we must round it down so its 831 cents which is 8.31 EUR. tax amount is 9.9 - 8.31 = 1.59 so in total it’s always 9.9. We do this to avoid wrong rounding, bc subtotal is 100% correct here, but then the tax amount must be 1.59.

Got it, one option may be to use the inclusive taxes option?

like so we dont have to calculate it at all just to specify tax% and total in the invoice?

Correct, it works out the tax amount from the total and rate.