diff --git a/README.md b/README.md
index bcbbd74..b114207 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,7 @@ Unreleased updates
 ------------------
 
 * Fix - WPML exchange rates (apply filter `wcml_raw_price_amount`)
+* Fix - tax class when taxes by cart items is on - applies the highest used tax. Thanks to [morvy](https://github.com/morvy)
 
 ## Credits
 
diff --git a/inc/class-pay4pay.php b/inc/class-pay4pay.php
index 903c30d..dfb8324 100644
--- a/inc/class-pay4pay.php
+++ b/inc/class-pay4pay.php
@@ -216,6 +216,25 @@ public function calculate_pay4payment() {
 						// WooCommerce Fee is always ex taxes. We need to subtract taxes, WC will add them again later.
 						if ( $taxable && $include_taxes ) {
 
+							// Apply the highest tax in the cart (see #65)
+							if ( $tax_class === 'inherit' ) {
+								$highestTaxRate = 0;
+								if ( $cart->get_cart() ) {
+									foreach ( $cart->get_cart() as $item ) {
+										if ( !$item['line_tax'] || !$item['line_total'] ) {
+											$itemTaxRate = 0;
+										} else {
+											$itemTaxRate = $item['line_tax'] / $item['line_total'];
+										}
+
+										if ( $itemTaxRate >= $highestTaxRate ) {
+											$highestTaxRate = $itemTaxRate;
+											$tax_class = $item['data']->tax_class;
+										}
+									}
+								}
+							}
+
 							$tax_rates = WC_Tax::get_rates( $tax_class );
 
 							$factor = 1;