Is it possible to refund tax on a partial order refund?
The substantial problem is, that magento doesn't know which tax factor to use. When there are no products which are refunded, there is no tax percentage.
I fixed the problem by just using the highest tax percentage I can find in the products, feel free to adjust to your use case.
The tax is calculated in calculateTaxForRefundAdjustment at the end of the class.
config.xml
<?xml version="1.0"?>
<config>
<modules>
<Project_RefundPartialCreditmemoWithTax>
<version>1.0.0</version>
</Project_RefundPartialCreditmemoWithTax>
</modules>
<global>
<models>
<project_refundpartialcreditmemowithtax>
<class>Project_RefundPartialCreditmemoWithTax_Model</class>
</project_refundpartialcreditmemowithtax>
</models>
<sales>
<order_creditmemo>
<totals>
<tax>
<class>project_refundpartialcreditmemowithtax/order_creditmemo_total_tax</class>
</tax>
</totals>
</order_creditmemo>
</sales>
</global>
</config>
app/code/local/Project/RefundPartialCreditmemoWithTax/Model/Order/Creditmemo/Total/Tax.php
<?php
class Project_RefundPartialCreditmemoWithTax_Model_Order_Creditmemo_Total_Tax
extends Mage_Sales_Model_Order_Creditmemo_Total_Tax
{
public function collect(Mage_Sales_Model_Order_Creditmemo $creditmemo)
{
$shippingTaxAmount = 0;
$baseShippingTaxAmount = 0;
$totalHiddenTax = 0;
$baseTotalHiddenTax = 0;
$order = $creditmemo->getOrder();
list($totalTax, $baseTotalTax) = $this->calculateTaxForRefundAdjustment($creditmemo);
/** @var $item Mage_Sales_Model_Order_Creditmemo_Item */
foreach ($creditmemo->getAllItems() as $item) {
$orderItem = $item->getOrderItem();
if ($orderItem->isDummy()) {
continue;
}
$orderItemTax = $orderItem->getTaxInvoiced();
$baseOrderItemTax = $orderItem->getBaseTaxInvoiced();
$orderItemHiddenTax = $orderItem->getHiddenTaxInvoiced();
$baseOrderItemHiddenTax = $orderItem->getBaseHiddenTaxInvoiced();
$orderItemQty = $orderItem->getQtyInvoiced();
if (($orderItemTax || $orderItemHiddenTax) && $orderItemQty) {
/**
* Check item tax amount
*/
$tax = $orderItemTax - $orderItem->getTaxRefunded();
$baseTax = $baseOrderItemTax - $orderItem->getTaxRefunded();
$hiddenTax = $orderItemHiddenTax - $orderItem->getHiddenTaxRefunded();
$baseHiddenTax = $baseOrderItemHiddenTax - $orderItem->getBaseHiddenTaxRefunded();
if (!$item->isLast()) {
$availableQty = $orderItemQty - $orderItem->getQtyRefunded();
$tax = $creditmemo->roundPrice($tax / $availableQty * $item->getQty());
$baseTax = $creditmemo->roundPrice($baseTax / $availableQty * $item->getQty(), 'base');
$hiddenTax = $creditmemo->roundPrice($hiddenTax / $availableQty * $item->getQty());
$baseHiddenTax = $creditmemo->roundPrice($baseHiddenTax / $availableQty * $item->getQty(), 'base');
}
$item->setTaxAmount($tax);
$item->setBaseTaxAmount($baseTax);
$item->setHiddenTaxAmount($hiddenTax);
$item->setBaseHiddenTaxAmount($baseHiddenTax);
$totalTax += $tax;
$baseTotalTax += $baseTax;
$totalHiddenTax += $hiddenTax;
$baseTotalHiddenTax += $baseHiddenTax;
}
}
$invoice = $creditmemo->getInvoice();
if ($invoice) {
//recalculate tax amounts in case if refund shipping value was changed
if ($order->getBaseShippingAmount() && $creditmemo->getBaseShippingAmount()) {
$taxFactor = $creditmemo->getBaseShippingAmount() / $order->getBaseShippingAmount();
$shippingTaxAmount = $invoice->getShippingTaxAmount() * $taxFactor;
$baseShippingTaxAmount = $invoice->getBaseShippingTaxAmount() * $taxFactor;
$totalHiddenTax += $invoice->getShippingHiddenTaxAmount() * $taxFactor;
$baseTotalHiddenTax += $invoice->getBaseShippingHiddenTaxAmount() * $taxFactor;
$shippingTaxAmount = $creditmemo->roundPrice($shippingTaxAmount);
$baseShippingTaxAmount = $creditmemo->roundPrice($baseShippingTaxAmount, 'base');
$totalHiddenTax = $creditmemo->roundPrice($totalHiddenTax);
$baseTotalHiddenTax = $creditmemo->roundPrice($baseTotalHiddenTax, 'base');
$totalTax += $shippingTaxAmount;
$baseTotalTax += $baseShippingTaxAmount;
}
} else {
$orderShippingAmount = $order->getShippingAmount();
$baseOrderShippingAmount = $order->getBaseShippingAmount();
$baseOrderShippingRefundedAmount = $order->getBaseShippingRefunded();
$shippingTaxAmount = 0;
$baseShippingTaxAmount = 0;
$shippingHiddenTaxAmount = 0;
$baseShippingHiddenTaxAmount = 0;
$shippingDelta = $baseOrderShippingAmount - $baseOrderShippingRefundedAmount;
if ($shippingDelta > $creditmemo->getBaseShippingAmount()) {
$part = $creditmemo->getShippingAmount() / $orderShippingAmount;
$basePart = $creditmemo->getBaseShippingAmount() / $baseOrderShippingAmount;
$shippingTaxAmount = $order->getShippingTaxAmount() * $part;
$baseShippingTaxAmount = $order->getBaseShippingTaxAmount() * $basePart;
$shippingHiddenTaxAmount = $order->getShippingHiddenTaxAmount() * $part;
$baseShippingHiddenTaxAmount = $order->getBaseShippingHiddenTaxAmount() * $basePart;
$shippingTaxAmount = $creditmemo->roundPrice($shippingTaxAmount);
$baseShippingTaxAmount = $creditmemo->roundPrice($baseShippingTaxAmount, 'base');
$shippingHiddenTaxAmount = $creditmemo->roundPrice($shippingHiddenTaxAmount);
$baseShippingHiddenTaxAmount = $creditmemo->roundPrice($baseShippingHiddenTaxAmount, 'base');
} elseif ($shippingDelta == $creditmemo->getBaseShippingAmount()) {
$shippingTaxAmount = $order->getShippingTaxAmount() - $order->getShippingTaxRefunded();
$baseShippingTaxAmount = $order->getBaseShippingTaxAmount() - $order->getBaseShippingTaxRefunded();
$shippingHiddenTaxAmount = $order->getShippingHiddenTaxAmount()
- $order->getShippingHiddenTaxRefunded();
$baseShippingHiddenTaxAmount = $order->getBaseShippingHiddenTaxAmount()
- $order->getBaseShippingHiddenTaxRefunded();
}
$totalTax += $shippingTaxAmount;
$baseTotalTax += $baseShippingTaxAmount;
$totalHiddenTax += $shippingHiddenTaxAmount;
$baseTotalHiddenTax += $baseShippingHiddenTaxAmount;
}
$allowedTax = $order->getTaxInvoiced() - $order->getTaxRefunded() - $creditmemo->getTaxAmount();
$allowedBaseTax = $order->getBaseTaxInvoiced() - $order->getBaseTaxRefunded()
- $creditmemo->getBaseTaxAmount();
$allowedHiddenTax = $order->getHiddenTaxInvoiced() + $order->getShippingHiddenTaxAmount()
- $order->getHiddenTaxRefunded() - $order->getShippingHiddenTaxRefunded();
$allowedBaseHiddenTax = $order->getBaseHiddenTaxInvoiced() + $order->getBaseShippingHiddenTaxAmount()
- $order->getBaseHiddenTaxRefunded() - $order->getBaseShippingHiddenTaxRefunded();
$totalTax = min($allowedTax, $totalTax);
$baseTotalTax = min($allowedBaseTax, $baseTotalTax);
$totalHiddenTax = min($allowedHiddenTax, $totalHiddenTax);
$baseTotalHiddenTax = min($allowedBaseHiddenTax, $baseTotalHiddenTax);
$creditmemo->setTaxAmount($creditmemo->getTaxAmount() + $totalTax);
$creditmemo->setBaseTaxAmount($creditmemo->getBaseTaxAmount() + $baseTotalTax);
$creditmemo->setHiddenTaxAmount($totalHiddenTax);
$creditmemo->setBaseHiddenTaxAmount($baseTotalHiddenTax);
$creditmemo->setShippingTaxAmount($shippingTaxAmount);
$creditmemo->setBaseShippingTaxAmount($baseShippingTaxAmount);
$creditmemo->setGrandTotal($creditmemo->getGrandTotal() + $totalTax + $totalHiddenTax);
$creditmemo->setBaseGrandTotal($creditmemo->getBaseGrandTotal() + $baseTotalTax + $baseTotalHiddenTax);
return $this;
}
/**
* @param Mage_Sales_Model_Order_Creditmemo $creditmemo
* @return array
*/
private function calculateTaxForRefundAdjustment(Mage_Sales_Model_Order_Creditmemo $creditmemo)
{
/** @var Mage_Sales_Model_Resource_Order_Item_Collection $orderItems */
$orderItems = $creditmemo->getOrder()->getItemsCollection();
$taxPercentage = 0;
foreach ($orderItems as $item) {
$taxPercentage = max($taxPercentage, $item->getTaxPercent() / 100);
}
$totalAdjustment = $creditmemo->getAdjustmentPositive() - $creditmemo->getAdjustmentNegative();
$baseTotalAdjustment = $creditmemo->getBaseAdjustmentPositive() - $creditmemo->getBaseAdjustmentNegative();
// Adjustment values already include tax in my case. Modify calculation if you're entering values without tax
$totalAdjustmentTax = $totalAdjustment / ($taxPercentage + 1) * $taxPercentage;
$baseTotalAdjustmentTax = $baseTotalAdjustment / ($taxPercentage + 1) * $taxPercentage;
$creditmemo->setGrandTotal($creditmemo->getGrandTotal() - $totalAdjustmentTax);
$creditmemo->setBaseGrandTotal($creditmemo->getBaseGrandTotal() - $baseTotalAdjustmentTax);
return [$totalAdjustmentTax, $baseTotalAdjustmentTax];
}
}
You will find the code that deals with this in the class Mage_Sales_Model_Order_Creditmemo_Total_Tax.
The line of code $part = $creditmemo->getShippingAmount()/$orderShippingAmount; (located at line 116) clearly shows this is specifically coded to only calculate the taxes as per the shippingAmount field from the creditMemo form.
The obvious change is to adjust that code to also use the "Adjustment refund" field.
You can't actually rewrite this class, due to how magento instantiates it as part of the totals collector subsystem, in the creditmemo calculations.
You can however adjust the collector to use your own version of the class, so all is not lost.
So, in your own module you will place the following code in the config.xml. It goes inside the <global> elements
<global>
<sales>
<order_creditmemo>
<totals>
<tax>
<class>NAMESPACE_MODULE/order_creditmemo_total_tax</class>
<after>subtotal</after>
</tax>
</totals>
</order_creditmemo>
</sales>
<global>
Now you will create the class file NAMESPACE/MODULE/Model/Order/Creditmemo/Total/Tax, which extends the core file.
class NAMESPACE_MODULE_Model_Order_Creditmemo_Total_Tax extends Mage_Sales_Model_Order_Creditmemo_Total_Tax
You will need to copy the entire `collect' method form the core class to your new file.
Add the following code at line 114 (just after the code $shippingDelta = $baseOrderShippingAmount - $baseOrderShippingRefundedAmount)
/** adjust to also calculate tax on the adjustment value **/
$adjustment = ($creditmemo->getAdjustment() > 0)?$creditmemo->getAdjustment():$creditmemo->getShippingAmount();
if($creditmemo->getAdjustment() > 0 && $creditmemo->getShippingAmount() > 0) {
$adjustment = $creditmemo->getAdjustment() + $creditmemo->getShippingAmount();
}
/** end adjustment **/
and adjust line 116 from $part = $creditmemo->getShippingAmount()/$orderShippingAmount; to $part = $adjustment/$orderShippingAmount;
This will then effectively use either the Shipping Amount or the Adjustment Amount in the calculation.