diff --git a/user/ajax/ajax_item_edit.php b/user/ajax/ajax_item_edit.php
index 424bd9dd..a605744c 100644
--- a/user/ajax/ajax_item_edit.php
+++ b/user/ajax/ajax_item_edit.php
@@ -12,6 +12,7 @@ $item_quantity = floatval($row['item_quantity']);
 $item_price = floatval($row['item_price']);
 $item_created_at = nullable_htmlentities($row['item_created_at']);
 $tax_id = intval($row['item_tax_id']);
+$product_id = intval($row['item_product_id']);
 
 // Generate the HTML form content using output buffering.
 ob_start();
@@ -25,6 +26,7 @@ ob_start();
 </div>
 <form action="post.php" method="post" autocomplete="off">
     <input type="hidden" name="item_id" value="<?php echo $item_id; ?>">
+    <input type="hidden" name="product_id" value="<?php echo $product_id; ?>">
     
     <div class="modal-body">
         <div class="form-group">
diff --git a/user/invoice.php b/user/invoice.php
index bfab6a67..0867d6e6 100644
--- a/user/invoice.php
+++ b/user/invoice.php
@@ -161,7 +161,7 @@ if (isset($_GET['invoice_id'])) {
     $invoice_badge_color = getInvoiceBadgeColor($invoice_status);
 
     //Product autocomplete
-    $products_sql = mysqli_query($mysqli, "SELECT product_name AS label, product_description AS description, product_price AS price, product_tax_id AS tax FROM products WHERE product_archived_at IS NULL");
+    $products_sql = mysqli_query($mysqli, "SELECT product_name AS label, product_description AS description, product_price AS price, product_tax_id AS tax, product_id AS prod_id FROM products WHERE product_archived_at IS NULL");
 
     if (mysqli_num_rows($products_sql) > 0) {
         while ($row = mysqli_fetch_array($products_sql)) {
@@ -431,6 +431,7 @@ if (isset($_GET['invoice_id'])) {
                                     $item_total = floatval($row['item_total']);
                                     $item_created_at = nullable_htmlentities($row['item_created_at']);
                                     $tax_id = intval($row['item_tax_id']);
+                                    $item_product_id = intval($row['item_product_id']);
                                     $total_tax = $item_tax + $total_tax;
                                     $sub_total = $item_price * $item_quantity + $sub_total;
                                     ?>
@@ -475,7 +476,8 @@ if (isset($_GET['invoice_id'])) {
                                 ?>
                                 <tr class="d-print-none" <?php if ($invoice_status == "Paid" || $invoice_status == "Cancelled" || lookupUserPermission("module_sales") <= 1) { echo "hidden"; } ?>>
                                     <form action="post.php" method="post" autocomplete="off">
-                                        <input type="hidden" name="invoice_id" value="<?php echo $invoice_id; ?>">
+                                        <input type="hidden" name="invoice_id" value="<?= $invoice_id ?>">
+                                        <input type="hidden" id="product_id" name="product_id" value="<?= $item_product_id ?>">
                                         <input type="hidden" name="item_order" value="<?php echo mysqli_num_rows($sql_invoice_items) + 1; ?>">
                                         <td></td>
                                         <td>
@@ -778,6 +780,7 @@ require_once "../includes/footer.php";
                 $("#qty").val(1); // Product quantity field automatically make it a 1
                 $("#price").val(ui.item.price); // Product price field
                 $("#tax").val(ui.item.tax); // Product tax field
+                $("#product_id").val(ui.item.prod_id); // Product ID field
                 return false;
             }
         });
diff --git a/user/post/invoice.php b/user/post/invoice.php
index c5d704ba..ad4c37af 100644
--- a/user/post/invoice.php
+++ b/user/post/invoice.php
@@ -518,9 +518,16 @@ if (isset($_POST['add_invoice_item'])) {
     $price = floatval($_POST['price']);
     $tax_id = intval($_POST['tax_id']);
     $item_order = intval($_POST['item_order']);
+    $product_id = intval($_POST['product_id']);
 
     $subtotal = $price * $qty;
+    
+    // Update Product Inventory
+    if ($product_id) {
+        mysqli_query($mysqli,"INSERT INTO product_stock SET stock_qty = -$qty, stock_note = 'QTY $qty - Invoice $invoice_id', stock_product_id = $product_id");
+    }
 
+    // Tax
     if ($tax_id > 0) {
         $sql = mysqli_query($mysqli,"SELECT * FROM taxes WHERE tax_id = $tax_id");
         $row = mysqli_fetch_array($sql);
@@ -532,7 +539,7 @@ if (isset($_POST['add_invoice_item'])) {
 
     $total = $subtotal + $tax_amount;
 
-    mysqli_query($mysqli,"INSERT INTO invoice_items SET item_name = '$name', item_description = '$description', item_quantity = $qty, item_price = $price, item_subtotal = $subtotal, item_tax = $tax_amount, item_total = $total, item_order = $item_order, item_tax_id = $tax_id, item_invoice_id = $invoice_id");
+    mysqli_query($mysqli,"INSERT INTO invoice_items SET item_name = '$name', item_description = '$description', item_quantity = $qty, item_price = $price, item_subtotal = $subtotal, item_tax = $tax_amount, item_total = $total, item_order = $item_order, item_tax_id = $tax_id, item_product_id = $product_id, item_invoice_id = $invoice_id");
 
     // Get Discount and Invoice Details
     $sql = mysqli_query($mysqli,"SELECT * FROM invoices WHERE invoice_id = $invoice_id");
@@ -691,6 +698,8 @@ if (isset($_GET['delete_invoice_item'])) {
     $row = mysqli_fetch_array($sql);
     $invoice_id = intval($row['item_invoice_id']);
     $item_name = sanitizeInput($row['item_name']);
+    $item_quantity = floatval($row['item_quantity']);
+    $item_product_id = intval($row['item_product_id']);
     $item_subtotal = floatval($row['item_subtotal']);
     $item_tax = floatval($row['item_tax']);
     $item_total = floatval($row['item_total']);
@@ -707,6 +716,11 @@ if (isset($_GET['delete_invoice_item'])) {
 
     mysqli_query($mysqli,"DELETE FROM invoice_items WHERE item_id = $item_id");
 
+    // Return Product Inventory
+    if ($item_product_id) {
+        mysqli_query($mysqli,"INSERT INTO product_stock SET stock_qty = $item_quantity, stock_note = 'Returned QTY $item_quantity back to stock from Invoice $invoice_id', stock_product_id = $item_product_id");
+    }
+
     logAction("Invoice", "Delete", "$session_name removed item $item_name from invoice $invoice_prefix$invoice_number", $client_id, $invoice_id);
 
     flash_alert("Item <strong>$item_name</strong> removed from invoice", 'error');