Ставка НДС в зависимости от местоположения 1С-Битрикс

price_provider.php

<?php

use Bitrix\Main;
use Bitrix\Main\Loader;
    
Loader::includeModule("catalog");

\Bitrix\Main\EventManager::getInstance()->addEventHandler(
    'sale',
    'OnSaleBasketBeforeSaved',
    'OnSaleBasketBeforeSavedHandler'
);


function OnSaleBasketBeforeSavedHandler(Main\Event $event)
{
    $basket = $event->getParameter("ENTITY");
    foreach ($basket as &$basketItem) {
        $basketItem->setFields(array("PRODUCT_PROVIDER_CLASS" => "CustomCatalogProvider"));
    }
}


class CustomCatalogProvider extends \CCatalogProductProvider
{
    /**
     * GetProductData
     *
     * @param  mixed $params
     * @return void
     */
    public static function GetProductData($params)
    {
        $result = parent::GetProductData($params);
        $session = \Bitrix\Main\Application::getInstance()->getSession();
        $vatRate = !empty($session->has('CUSTOM_VAT_RATE')) ? $session->has('CUSTOM_VAT_RATE') : 0.21; //set IVA 21% by default
        $result['VAT_RATE'] = $vatRate;
        $result['VAT_INCLUDED'] = 'N';
        return $result;
    }
}

\Bitrix\Main\EventManager::getInstance()->addEventHandler(
    'sale',
    'OnSalePropertyValueSetField',
    'OnSalePropertyValueSetFieldHandler'
);

/**
 * OnSalePropertyValueSetFieldHandler
 *
 * @param  mixed $event
 * @return void
 */
function OnSalePropertyValueSetFieldHandler(\Bitrix\Main\Event $event)
{
    $entity = $event->getParameter("ENTITY");
    $arOrderVals = $entity->getFields()->getValues();
    $codeField = $arOrderVals['CODE'];

    if ($codeField == 'LOCATION') {
        $cityCode = $event->getParameter('VALUE');
        if (!empty($cityCode)) {
            $arCity = \Bitrix\Sale\Location\LocationTable::getList(array(
                'filter' => [
                    'CODE' => $cityCode
                ],
                'select' => ['*'],
            ))->fetch();
            
            if ($arCity['PARENT_ID'] > 0) {
                $queryId = $arCity['PARENT_ID'];
            } else {
                $queryId = $arCity['ID'];
            }

            $locationGroup = \Bitrix\Sale\Location\GroupLocationTable::getList(array(
                'filter' => [
                    'LOCATION_ID' => $queryId
                ],
                'select' => ['*'],
            ))->fetch();

            $groupId = $locationGroup['LOCATION_GROUP_ID'];
            if ($groupId == 1) { //sin IVA
                $vatRate = 0;
            } elseif ($groupId == 2) { //IVA 21%
                $vatRate = 0.21;
            } else {
                $vatRate = 0.07; //IVA 7%
            }
            $session->set('CUSTOM_VAT_RATE', $vatRate);
        }
    }
}