VAT Bug Calculator : Floor or Truncate instead of a proper Round ??

[BatGo]

 

Hi,

I'm creating a merchand website under 1.7.5 but I noticed that I've got a 1 cent € error between my local order software and Prestashop.

After investigation : the difference is about the VAT. And it's incredible that no one talk about that on Internet.

So I decided to install a new Presta (last version) to check if the problem was on my configuration or not.

So not.

To reproduce the problem : it's very simple.

• Back Office : Set the B2B and HT price (French setup / 20% VAT).
• Create a product (default VAT 20%) with combination.
• Just add 1 declination with the price of 0.70€ HT (and a large stock)
• Set a specific price : -25% from qtty 250
• Add a delivery 12€ HT.
• Font Office : add 459 to your basket and check it.

Here you are a product line : 0.70 * 459 * 0.75 = 240.975€ = 240.98€ HT (line round).

Add 12€ HT delivery

So total is 240.98 + 12 = 252.98 € HT (prestashop is okay with me).

There : all is right. But not apply the VAT.

252.98 * 1.2 = 303.576 € TTC

So.. 303.58€ for normal people but 303.57€ for Prestashop.

What’s happened ? VAT calculator : 50.59 instaed of 50.6€ (and it's written 50.59 on the bill).

The absolute only way that I found to get the same result is to calculate the VAT after everythings and to not round anywhere : (0.7*459*0.75+12)*1.2 = 303.57€

I think VAT calculation does not respect the previous round line.

 

Thanks.

Baptiste.

[BatGo]

https://support.facturation.pro/hc/fr/articles/210223943-Quelle-est-la-règle-appliquée-pour-le-calcul-de-la-TVA-#:~:text=La méthode dite de "l,enfin arrondir le résultat final.

 

(topics in french)

 

It's related about sum before or after rounded.

[BatGo]

html\src\Core\Cart\CartRow.php

    protected function applyRound() ou protected function applyRound() //selon la version
    {
        ...
            case self::ROUND_MODE_LINE:
                // round line result
                $tva_found = $this->initialUnitPrice->getTaxIncluded()/$this->initialUnitPrice->getTaxExcluded(); //ADD
                $this->finalTotalPrice = new AmountImmutable(
                    // $tools->round($this->initialUnitPrice->getTaxIncluded() * $quantity, $this->precision),
                    round(round($this->initialUnitPrice->getTaxExcluded() * $quantity, 2) * $tva_found, 2), //ADD
                    $tools->round($this->initialUnitPrice->getTaxExcluded() * $quantity, $this->precision)
                );
                break;