diff --git a/includes/class-wc-discounts.php b/includes/class-wc-discounts.php
index 8b39a8d992e..6f8502612a4 100644
--- a/includes/class-wc-discounts.php
+++ b/includes/class-wc-discounts.php
@@ -665,10 +665,6 @@ class WC_Discounts {
 	protected function validate_coupon_minimum_amount( $coupon ) {
 		$subtotal = wc_remove_number_precision( $this->get_object_subtotal() );
 
-		if ( is_a( $this->object, 'WC_Order' ) && $this->object->get_prices_include_tax() ) {
-			$subtotal += round( $this->object->get_total_tax(), wc_get_price_decimals() );
-		}
-
 		if ( $coupon->get_minimum_amount() > 0 && apply_filters( 'woocommerce_coupon_validate_minimum_amount', $coupon->get_minimum_amount() > $subtotal, $coupon, $subtotal ) ) {
 			/* translators: %s: coupon minimum amount */
 			throw new Exception( sprintf( __( 'The minimum spend for this coupon is %s.', 'woocommerce' ), wc_price( $coupon->get_minimum_amount() ) ), 108 );
@@ -688,10 +684,6 @@ class WC_Discounts {
 	protected function validate_coupon_maximum_amount( $coupon ) {
 		$subtotal = wc_remove_number_precision( $this->get_object_subtotal() );
 
-		if ( is_a( $this->object, 'WC_Order' ) && $this->object->get_prices_include_tax() ) {
-			$subtotal += round( $this->object->get_total_tax(), wc_get_price_decimals() );
-		}
-
 		if ( $coupon->get_maximum_amount() > 0 && apply_filters( 'woocommerce_coupon_validate_maximum_amount', $coupon->get_maximum_amount() < $subtotal, $coupon ) ) {
 			/* translators: %s: coupon maximum amount */
 			throw new Exception( sprintf( __( 'The maximum spend for this coupon is %s.', 'woocommerce' ), wc_price( $coupon->get_maximum_amount() ) ), 112 );
@@ -916,7 +908,8 @@ class WC_Discounts {
 		if ( is_a( $this->object, 'WC_Cart' ) ) {
 			return wc_add_number_precision( $this->object->get_displayed_subtotal() );
 		} elseif ( is_a( $this->object, 'WC_Order' ) ) {
-			return wc_add_number_precision( $this->object->get_subtotal() );
+			$subtotal = wc_add_number_precision( $this->object->get_subtotal() );
+			return $this->object->get_prices_include_tax() ? $subtotal + round( $this->object->get_total_tax(), wc_get_price_decimals() ) : $subtotal;
 		} else {
 			return array_sum( wp_list_pluck( $this->items, 'price' ) );
 		}