Can I change the taxes on a quote item in magento2 programmatically?

Question

I need to change the tax rate on quote items in a magento2 checkout process that is entirely done programmatically.

What I've found from various resources here on stackoverflow is that is possible to change the quote item's product tax rate

$item->getProduct()->setTaxClassId(1);

In my quote, however, I have many quote items, but they are the all the same catalog-product, only with differrent options aplied to them. Now, when I set the products tax rate like shown above, the last tax-class-id I set is used for ALL items in the quote.

I need a way to set the tax on the quote item directly. But

$item->setTaxPercent(4)

(e.g.) has no effect.

Answer 1

That's how you should do it:

Change the file app/code/Vendor/Package/etc/di.xml in your custom package by adding the line

<type name="Magento\Checkout\Model\Cart">
    <plugin name="interceptAddingProductToCart" type="Vendor\Package\Model\Checkout\Cart\Plugin" sortOrder="10" disabled="false"/>
</type>

Create the plugin

app/code/Vendor/Package/Model/Checkout/Cart/Plugin.php

Now, add the content to the file above:

<?php

namespace Vendor\Package\Model\Checkout\Cart;

class Plugin
{
    /**
     * @var \Magento\Quote\Model\Quote
     */
    protected $quote;

    /**
     * Plugin constructor.
     *
     * @param \Magento\Checkout\Model\Session $checkoutSession
     */
    public function __construct(
        \Magento\Checkout\Model\Session $checkoutSession
    ) {
        $this->quote = $checkoutSession->getQuote();
    }

    public function beforeAddProduct($subject, $productInfo, $requestInfo = null)
    {
        # Do something, here for instance, it remove TAX for giftvouchers
        if ($productInfo->getTypeId() == 'giftvoucher') {
            $productInfo->setTaxClassId(0);
        }

        return [$productInfo, $requestInfo];
    }
}

Answer 2

Yes, you can change.. You can try out below tricks:

1. create custom tax rules and rates as per current quote address, this will apply tax rate to each product. Product rate you can calculate and save.

2. use FPT , you can also customize it.. sales_quote_collect_totals_before use this event to change the fixed product tax value, this will add/change fixed amount to each product.