Today I found that paypal just ignores the ‘shipping’ parameter when dealing with a third party cart.

If you find yourself with this problem the workaround posted on the X forums by PayPal themselves is to calculate shipping costs on your side and send them using the ‘handling_cart’ parameter.

It’s just dumb to have to use a parameter that is not referred to shipping to include the shipping, but until this is resolved, this workaround should do the trick. At least if worked for me!

UPDATE: Looks like it’s not just a workaround, but the expected behaviour, it’s just that the documentation is poorly written, leading the developer to think that ‘shipping’ will apply to a cart, when in fact it will not, everything is expected to be sent using the ‘handling_cart’ param