Sales Tax Not Calculating on Negative Sales Line

We have a situation where the sales tax calculates properly when entering an order for a customer, but when we enter a negative sales line for the same customer the tax is not calculating at all. Is there a setup somewhere or parameter that could possible drive this behavior? Has anyone experienced this before? AX2009

Hello Shaun,

Have you checked the sales tax group and item sales tax group on your sales order with the negative line and how the sales tax group and item sales tax group is setup?

Once you are in the sales tax form, select ‘setup - sales tax’ to see what sales tax code AX can identify.

Hope this helps.


Hello Ludwig,

Thanks for the advice. I’ve created a sales order with 2 sales lines of an identical item. On 1 sales line I enter a positive qty and the other I enter a negative qty. The item sales tax group and the sales tax group are the same for both lines. When I post the invoice only the positive line includes the tax, the negative line has no tax.

I’ve looked through all the fields and tab in the sales tax group, sales tax code, and item sales tax group, but I can’t find anything that would make this behavior.



Looks like a weakness in a customization that we have made. Thanks anyway.