Tax calculated incorrectly when discount applied to payment method

If I use a promotion to apply a 1% discount to the cart total if a specific payment method is used then the sales tax is calculated incorrectly.

Not sure how the tax is arrived at because it does not appear to correspond to anything

I believe 2.1.0+ have the ability to specify tax on the subtotal after discounts or pre-discounts. It’s in Admin->Settings->General

Tax calculation method based on:

[quote name=‘racingsolution’]I believe 2.1.0+ have the ability to specify tax on the subtotal after discounts or pre-discounts. It’s in Admin->Settings->General

Tax calculation method based on:[/QUOTE]

Settings are either Subtotal or Unit Price

If Unit Price is selected then tax is calculated prior to discounts I presume.

I have my cart set to Subtotal which is after discounts, but it is still calculating tax incorrectly for a promotion based discount on payment method, must be a bug

In fact it appears that any ‘Order discount:’ discount in a promotion results in the wrong tax amount

Ya that sounds like the same ole bug we’ve had for the past few versions… thought it got fixed in 2.1 but I guess not

Hi there,

I think my problem is about same as this one. We are on 2.12.

For companies we offer to send them an invoice by snail mail that they can pay later.

We charge 2,50 for this.

The problem is that C-cart doesn’t add tax to this amount, which it should. (To make life a bit easier, tax on shipping or extra costs like this is the same as on the product you sell in the Netherlands).

Anyone knows how to fix this issue? Is this a bug?


Hi Guys,

We seem to have a similar problem with this. On our front page price says including tax which is incorrect. However once you click on product the correct price including vat is displayed. Would be helpful if anybody knows how to solve this. We are using vers:2.1.1

I reported this as a bug and CS blatantly calls this “a feature that is not available in CS-cart” and closes the bug thread. Ridiculous!

it is already a feature in CS-cart that does not work the way it should, I call that a bug!

Check [url][/url]

Nobody has an opinion about this?

I add 1 product to the cart, cost is 1.60 plus tax (.32 tax)

I enter promotion code at checkout which entitles me to free delivery and 100% discount on said product, delivery calculates as free, product calculates as free, but tax on the product is still in the cart(.32)…weird.

SO the customer now has to pay the tax amount on a product he gets for free???

Come on CS whats the score


The Subtotal or Item tax calculation option doesn’t help this since Sub-Total is before discount… that’s why you can get 100% off your order and still be charged tax.

This is a problem, and a bug… anyone ever get an answer or a fix??



I am also interested in whether this issue has been 100% resolved.

this is a total bug and needs to be fixed by the cs cart team. If i make a 100% off discount code, why should my users pay tax on what’s supposed to be a free purchase.

some suggestions how magento handle tax calculation:


[quote name='Captain' timestamp='1348214991' post='145493']

some suggestions how magento handle tax calculation:…al-tax-settings


You did see this topic is very old and the problem has been fixed?

So this still appears to be a problem

I agree. I cannot believe this is not fixed. I need the tax on the sub-total excluding the discount/promotion. Our taxes are not adding up correctly.

The sub-total is discounted before its taxed which throws the correct tax off point.

We have encountered similar behavior in our shipping cost calculation module when discounts were applied through promotions. Perhaps you have a similar problem in the module that you use to calculate delivery.

Contact the module developer