[SOLVED] VAT calculation problem when using reductions (Prestashop 1.4.6.2)

[Tom_Rufener]

I ran into a VAT calculation problem in Prestashop 1.4.6.2 when using reductions:

 

One of my shops uses 8% VAT for Swiss customers and no tax (!) for customers from Germany and Austria because there's no VAT on exports from Switzerland to other countries. There's only one currency in use, CHF (Swiss Francs). Today, I realized that something is wrong with the tax calculation when using reductions; a customer from Germany placed an order and had a tax deduction which was double the amount it should have been:

• The price of the product that the customer ordered is CHF 299.00 incl. 8% VAT; that's the "retail price with tax" (without reduction)
  
• We sell this product with a reduction of CHF 140.00, so the resulting price incl. 8% VAT is CHF 159.00
  
• Because there's no VAT on exports from Switzerland to other countries, the VAT amount should be calculated and deducted like this: 159.00 / 108 * 8 = 11.77 CHF (VAT amount) and then CHF 159.00 - 11.77 CHF = CHF 147.23 (that would be correct)
  

But in this case, Prestashop calculated as follows:

• CHF 299.00 / 108 * 8 = CHF 22.14 (VAT amount, notice that the wrong amount is used for tax calculations; CHF 299.00 instead of CHF 159.00; that's the retail price without reduction!) and then
  
• CHF 159.00 - CHF 22.14 = 136.86 (see the difference of CHF 10.37 compared to the correct amount stated above?)
  

The customer didn't use any vouchers or other discount types. Does anyone of you know how to solve this issue? This is causing a loss of money each time a customer from Germany or Austria places an order in my shop - and it gets even worse at higher amounts ... my shop offers reductions on almost all products in the catalogue.

 

 

Any help is greatly appreciated!

Tom