PayPal Express failing when customers add a shipping cost.

[MonsterMagic]

PayPal Express only works on my website if the customers chooses free shipping. If shipping is added PayPal refuse the payment. This is the response from PayPal:

Regarding the reason PayPal cannot fix this:

Shopify uses PayPal's ExpressCheckout API. The first step is "SetExpressCheckout" where Shopify sets up transactions. The next step is the customer approving the transaction. The third step is "DoExpressCheckoutPayment" which tells PayPal to attempt to capture the funds. PayPal then tells Shopify if the transaction succeeded.

Shopify specifically tells PayPal what to do and PayPal tells Shopify the outcome of what they requested. It is then up to Shopify to take action based on what PayPal returns. 

In this case, PayPal is telling Shopify that the transaction failed because the customer needs to approve the new higher amount. From step 6 below, Shopify must take action; however, they do not.

A specific example

An example of this occurring in one of your API requests with the Express Checkout Token EC-0NU13966KX623242Y is:

1. Shopify sends PayPal: SetExpressCheckout
   • paymentrequest_0_amt    "1.50"
     • This is the Total amount
   • paymentrequest_0_itemamt    "1.50"
   • paymentrequest_0_shippingamt    "0.00"
2. The customer Approves 1.50 as the total order amount
3. PayPal notifies Shopify of the Approval
4. Shopify sends PayPal: DoExpressCheckoutPayment
   • paymentrequest_0_amt    "3.85"
   • paymentrequest_0_itemamt    "1.50"
   • paymentrequest_0_shippingamt    "2.35"
5. PayPal tells Shopify the payment fails because 3.85 is greater than the approved amount of 1.50
6. End

I apologize for the inconvenience this has caused. Thank you for using PayPal, and have a wonderful day!

Has anyone else had similar problems and what is the fix?

Best,

Alex