diff --git a/cart-grain.go b/cart-grain.go
index a07ebf4..9d9fecf 100644
--- a/cart-grain.go
+++ b/cart-grain.go
@@ -311,8 +311,8 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 				if msg.Tax > 0 {
 					tax = int(msg.Tax)
 				}
-				total := int(msg.Price) * int(msg.Quantity)
-				taxAmount := GetTaxAmount(total, tax)
+
+				taxAmount := GetTaxAmount(int(msg.Price), tax)
 
 				c.Items = append(c.Items, &CartItem{
 					Id:          c.lastItemId,
@@ -466,13 +466,13 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 		} else {
 
 			orderLines := make([]*Line, 0, len(c.Items))
-			totalTax := 0
+
 			c.PaymentInProgress = true
 			c.Processing = true
 			for _, item := range c.Items {
 				total := int(item.Price) * item.Quantity
-				taxAmount := GetTaxAmount(total, item.Tax)
-				totalTax += taxAmount
+				taxAmount := int(item.Tax) * item.Quantity
+
 				orderLines = append(orderLines, &Line{
 					Type:           "physical",
 					Reference:      item.Sku,
@@ -491,7 +491,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 				PurchaseCurrency:   "SEK",
 				Locale:             "sv-se",
 				OrderAmount:        int(c.TotalPrice),
-				OrderTaxAmount:     totalTax,
+				OrderTaxAmount:     int(c.TotalTax),
 				OrderLines:         orderLines,
 				MerchantReference1: c.Id.String(),
 				MerchantURLS: &CheckoutMerchantURLS{