Tax calculation BUG!

**ErikAllan** · 24 Mar 2010, 12:45 PM

Hello

I think I´ve found a bug related to coupons and taxes.

SETTINGS:
- Zencart 1.3.8a
- Display prices with tax = TRUE
- Two tax rates, one 25% and one 6% (set to same priority = 1)
- Some products are set to 6% tax and some to 25% tax

PROBLEM:
When I add products with 6% tax to the shopping cart and use a discount coupon, the tax calculation fails. See the attached file. It only happens when I add products with 6% tax or combining products with 6% and 25% tax.

I have also made the code changes mentioned in these threads to solve other problems related to tax/coupons/shipping issues:

http://www.zen-cart.com/forum/showthread.php?t=43436

http://www.zen-cart.com/forum/showthread.php?t=124685

/Erik

**swguy** · 25 Mar 2010, 12:23 AM

This is a known problem in the 1.x series. You may want to consider not recalculating taxes and making the customer liable for the entire original tax if this is permitted in your country.

**ErikAllan** · 25 Mar 2010, 08:27 AM

Hi

Ok. Is there any work around to fix it? Where is the "known bug" documented?

What do you mean by "not recalculating taxes and making the customer liable for the entire original tax"? I think the Swedish law says I have to specify the 6% and 25% tax seperately on the invoice...

Thank you for trying to help

Best Regards
Erik

**swguy** · 25 Mar 2010, 11:24 AM

I mean in admin->modules->order total->coupons, set recalculate tax to none.

**ErikAllan** · 25 Mar 2010, 11:38 AM

Hello again

When I set Recalculate tax to none I get really strange results, see the attached file.

/Erik

**swguy** · 25 Mar 2010, 04:26 PM

Originally Posted by ErikAllan

Ok. Is there any work around to fix it? Where is the "known bug" documented?

http://www.zen-cart.com/forum/showthread.php?t=128368

**ErikAllan** · 25 Mar 2010, 08:29 PM

Ok, I understand... have to wait until 2.0 then.

I found a solution that works for me temporary though. If I set the "Include shipping" flag to TRUE, the tax calculation works. So the miscalculation has to do with this setting. I also laborated a little with the code in ot_coupon.php around line 374 where the tax logic for "Standard" recalculation is. If I have time I will dig deeper...

/Erik